1967 GMC 351 V-6, anythoughts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

shelby987 · 05-17-2005, 11:16 AM

I came across a 1967 GMC 3/4 ton, 2wd just down the street from me. It has the SM465 with the creeper, and a 351 V-6. The truck looks to be in good shape with the exception of some bad bondo, a couple of minor dings, and a couple of spots of rust.

The truck has factory A/C, the V-6, manual trans, 3/4ton running gear, and power brakes. Does anyone have any recommendations on this truck, is this a rare rig? (never seen this setup before personally). What price would be a good asking price?

Any inherent problems with the GMC V6's (have been reading up on the 6066gmctrucks.org site, and they sound like a pretty decent engine...parts availability an issue? What kind of mileage would you expect out of a truck with this setup?
Thanks
-Lee

70 shorty · 05-17-2005, 11:22 AM

all I can add is what I've read from this site, and that's that the 351 V6 is definitely preferrable to the 305 V6.

**CPNE** · 05-17-2005, 11:34 AM

Mileage is lousy, engine can't be killed. You've got to love a "truck" to want that combo. That being said, I'd be all over it, especially if it hasn't been hacked up.

If you plans include yanking the engine/drivetrain in favor of something more "modern", look elsewhere. The 351 was not at all common in light duty pickups. But don't think its gold either, its a niche market at best for those old beasts and not many people find them desireable.

shelby987 · 05-17-2005, 11:43 AM

What does "lousy" equate to, if I end up with this truck, it might end up being the 25mile round trip for a commuter vehicle...not horrible, but I would rather it not take 6 gallons for the trip.

Also, the site says there max RPM is around 3500, what would that put a max highway cruising speed at? (unsure of actual rear gearing).
Thanks

**CPNE** · 05-17-2005, 11:48 AM

10 mpg or so, but you'll get it loaded or standing still

. PM user Erl, he's got a V6 and knows a bunch about them

724wdcopper · 05-17-2005, 11:57 AM

i wouldn't go looking for performance parts, either, but cool truck nonetheless. like the others said, impossible to kill, low revving, stump-pulling, torque monster, then you go and add the granny 4 spd, you could get out and walk up a hill faster, but it will do it at idle. not sure it would be a good 25 mile commuter, unless you're on surface streets. highway probably not the daily option for this combo. sounds like a cool rig, even has air, huh? right on!

Dano69c10 · 05-17-2005, 01:56 PM

Check out this website, "6066gmcguy.org". There are v-6 info pages, and some performance upgrade pages. The v-6's he has on the site look way cool! Especially the magnum v-6. Love those valve covers!

Dano

http://www.6066gmcguy.org/305V6.htm
http://www.6066gmcguy.org/351V6.htm
http://www.6066gmcguy.org/performance.htm
http://www.6066gmcguy.org/Jolly-351v6.htm
http://www.6066gmcguy.org/Jolly-478v6.htm
http://www.6066gmcguy.org/Jolly-401v6.htm

Fred T · 05-17-2005, 03:19 PM

I agree with all of the above. Drove a lot of trucks with the old V6. It will pull anything you can hook on, but don't expect to get there in a hurry. Highway driving kills them, the crank is huge and balance is horrible. The high nickel block will last for 500K miles, but the rotating mass will self-destruct when operation over 2,500 rpm is sustained. And they make a heck of a racket when you throw a rod. Someone in GMC corporate loved the engine, but the customers hated them. About the only tasks I would consider one for would be local deliveries, parade duty or boat anchor.

Milage wasn't too bad, considering everything. Pickup with a 305 would get about 12. 2 ton with the 351 was 6 to 10. The 478 in a 5 ton got 4 to 8. I never drove a 401 in anything.

Give me a straight six any day of the week.

shelby987 · 05-17-2005, 07:39 PM

Just out of curiousity, and I am sure someone has asked, but with the search function being down.....since the engine is so torque happy, would it be possible to use the sm465 like a richmond 5 speed.....use the first lower gear (creeper) as first and put really high gears in the rear, like a set of 3.08 or maybe 2.8X....will this make it a little more highway friendly? I know on the richmond transmissions, they don't use overdrive, they have the same final drive ratio of 1:1, but have a much lower 1st gear to compensate (yes, aware the gear spacing on a 4 speed with a creeper will not be as ideal, just curious.
(I have yet to grenade an engine....maybe 3 or 4 transmissions, but no engines....hoping to keep my record).
Thanks

Fred T · 05-17-2005, 08:36 PM

With the 351 in a pickup you could do it, and you still wouldn't need first gear to start. 3.08 gears with 28" tires would make about 2600 rpm at 70 mph. You could run all day and night like that.

Be sure to visit Jolly's website, lots of good info. Adding either an HEI or Pertronix would help this engine. You should also be able to do a lot with the advance curves to help out your milage. And the Holley carb swap would help. It still won't be a speed demon, but should make a good, reliable driver for you.

Robert1970C20rstbukt · 05-17-2005, 11:25 PM

Also, if you can find one, it's possible to install one of the SM420's with a 4 speed auxillary overdrive transmission.

chevymad · 05-18-2005, 01:58 AM

Tons of torque. I'd definately put as tall of gears as you can find in it. I drove a 66 305 v/6, 3spd once. Was foolin with the column shift and took off.. Only realized I was allready in 3d instead of first when I didnt have to shift.

rwgregory · 05-18-2005, 03:24 AM

I'm on my second 3/4 ton GMC p/u w/305 V-6. Loved my '65 and have been kicking
myself ever since I sold it. FYI, my '65 got 10/11 mpg loaded or empty w/4.56 rear
gears & 33" tires. Only thing I ever did to it was split the exhaust into duals w/turbo
mufflers. Gained quite a bit of upper end and it had a nice rumble to boot!! I would
commute 22 miles each way, 5 days per week and take a 100/150 mile trip once or
twice each month with it. Only problems were exhaust manifold bolts would loosen up
and I would have to re-tighten them every 4/6 months, probably due to the majority
or my driving being freeway. In a nutshell, I think these were great TRUCKS!! and I beg you not to butcher/modernize it with more modern/mundane drivetrain.
Thanks for letting me rant,
rwgregory

shelby987 · 05-18-2005, 06:51 AM

so again, just out of curiousity, i have visited the 6066 page, and saw the holley 500 2brl carb upgrade and the buick dist. upgrade. Has anyone out there tried to run a similar adaptor plate with either a revamped factory tbi, or a holley tbi?
I have always been a big niche vehicle/engine fan, someone mentioned that the engine is poorly balanced, would it be possible during a rebuild to rebalance the crank/rods/pistons and see upwards of 5-6k redline? I can only assume that this would require valve spring and cam swaps at the sametime....possibly a port and polish would help a little. While the 6066 page is very informative, it doesn't seem like anyone has taken any steps to use the potential power of a "big block" v6.....and I have seen no mention of anyone that makes headers for this thing.....should I assume that means its a "you want 'em, you build 'em" kinda thing?
Thanks

**CPNE** · 05-18-2005, 09:32 AM

Quote:

Originally Posted by shelby987

so again, just out of curiousity, i have visited the 6066 page, and saw the holley 500 2brl carb upgrade and the buick dist. upgrade. Has anyone out there tried to run a similar adaptor plate with either a revamped factory tbi, or a holley tbi?
I have always been a big niche vehicle/engine fan, someone mentioned that the engine is poorly balanced, would it be possible during a rebuild to rebalance the crank/rods/pistons and see upwards of 5-6k redline? I can only assume that this would require valve spring and cam swaps at the sametime....possibly a port and polish would help a little. While the 6066 page is very informative, it doesn't seem like anyone has taken any steps to use the potential power of a "big block" v6.....and I have seen no mention of anyone that makes headers for this thing.....should I assume that means its a "you want 'em, you build 'em" kinda thing?
Thanks

What you're finding is that this engine is a bit of a dinasaur, with little in the way of aftermarket upgrades. Anything is possible with enough time, money and talent. Your real question is "Do I want a "truck" or do I want a "ride", that I can use for light duty truck use. It sound as if your goal is a small block with overdrive, with modern upgrades. If so this engine is not for you IMO. Good luck with whatever you decide to do.

67-Cowboy · 05-18-2005, 04:56 PM

I'll put it like this I would dearly love to have another one ! They are the perfect Cowboy truck; stock they will pull and out pull any and everything, just put her in granny and load 250 bales on the trailer and she never misses a lick. With a threespeed tranny and a car third member running 2.7? gears you are running 55 miles an hour at a idle. With this ratio you get a little better gas milage too, we got like 18 on a road trip once with a new rear end. We sold our's to buy a newer truck because they aren't real easy to find parts for in certain parts of the country.

Fred T · 05-18-2005, 05:55 PM

Quote:

Originally Posted by CPNE

What you're finding is that this engine is a bit of a dinasaur, with little in the way of aftermarket upgrades. Anything is possible with enough time, money and talent. Your real question is "Do I want a "truck" or do I want a "ride", that I can use for light duty truck use. It sound as if your goal is a small block with overdrive, with modern upgrades. If so this engine is not for you IMO. Good luck with whatever you decide to do.

In order to make a performer, rather than a driver, will be expensive. For enough $$$s, a good machinist could balance the engine. Unless you like to spend a lot of money just to be different, I would go with a V8. I have no problem with spending money to be different, I've done it myself. I just don't want to see you end up with something you won't be happy with.

The V6 is a love/hate monster. If you want a driver and don't want to be in a hurry, you can love it. Otherwise, you will end up hating it. Most of my experience comes from commercial driving of trucks that management bought on the cheap and we had to mis-use to get the job done. Had a 478 that we blew up 4 times in 100,000 miles. It was used as a road truck, yet 62 mph was wide open. The last time I drove it I picked up a piece of the block that was bigger than my hand.

724wdcopper · 05-18-2005, 08:03 PM

keep in mind also that if you're looking for a performance engine, the GMC V6 is significantly heavier than most small blocks. they were built as a truck engine with strength in mind, not weight savings for racing purposes. if you want a heavy performance engine, a BB chev would fit the bill better. if you fast rig, the V6's weight is going to be a hinderance. that's a lot of weight over the front end. but that said, i think engines that are a bit off the beaten 350 path are ultra cool. that's why i opted for an all aluminum buick 215 cid V8 for my 1929 chev streetrod. i'm still looking for parts (anyone have any), but that's the price you pay for individuality!

TP from Cntl PA · 05-18-2005, 09:52 PM

IMO they were one of the best engines of their time for a "WORK" truck(AKA pickup)............I got a 305 V-6 in a '69 GMC 1-ton and it will pull like mad! Like these other guys said, they don't like RPM's...........But will take about everything else you can throw at them with good service intervals.

I'd like to find a 3/4 ton with either a 305 or 351, 4spd, with 4x4...........Then bolt the gooseneck hitch in it and see how much weight you can get on it before you pull the ball out of the frame

IMO, definitly more awesome than a SBC powered truck!

BobS · 05-18-2005, 11:22 PM

Not much to add that hasn't already been said. If the tranny is original it should be an SM-420. If the rest of the equipment is original it's a pretty rare combination. I'd love to have one of these with AC. If you buy it, please leave it original, there are plenty of other trucks around if you want to modify one.

Bob

67_C-30 · 05-19-2005, 12:21 AM

As far as modding a V6 goes there is not a whole out there that I have found on Net, but I did see a Garrett Turbocharger installed on a 305E in a '66 GMC years ago. It was a unit off a Pontiac 301 Turbo Trans Am that used a suck through Q-jet carb. I saw this pre-Internet and I did not get pictures, but I've never forgotten about that thing. The guy did a very neat job with the plumbing and it actually looked like it could have come that way if you didn't know anything about them. He made a loop crossover pipe that went from manifold to manifold and then had a Y off that on the passenger side that went up to the turbo. He then had a bigger probably 3" pipe coming out the turbo going under the truck. That kind of turbo if you are not familiar bolts directly to the intake with a 3 bolt flange, and he made an adaptor for that and used the stock intake. He had the whole engine, including the intake side of the turbo, and the turbo carb adapter painted the factory V6 red. He had a big stock air cleaner on the Q jet that really covered it. I have included a picture of a 301 Pontiac Turbo engine and the turbo unit. Just imagine that set-up on a V6. Those type are dinosaurs also in respect to modern turbo units, but they made a sizeable gain on the 301's. The HP and TQ on a 301 Turbo is 210HP and 345 TQ compared to 150HP and 245TQ for a N/A engine, so it should have similiar effect on a GMC V6, since the 301 Poncho is a low revving engine with much more balancing issues than V6 has. The guy that built the truck claimed the engine was stock otherwise, and that the Turbo and 4bbl made it much more Torqueyer (if that's a word

) and it had much better overall power. He lit the tires up when he left the show, it had a very cool sound! I wish I had pics of it because it was really cool looking if nothing else!

shelby987 · 05-19-2005, 11:04 AM

would anyone happen to have an opinion as to the worth of a 3/4 ton, 351 V-6 GMC with (what I guess must have been) an SM420 (thought i read that the sm465 was picked up in 67...could be wrong), in a relatively stock form, and rust free? I know, I know, pictures, I am working on it.... :P
Thanks

Dano69c10 · 05-19-2005, 01:25 PM

Man I wish I could buy that truck!
Dano

05-17-2005, 11:16 AM	#1
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	1967 GMC 351 V-6, anythoughts I came across a 1967 GMC 3/4 ton, 2wd just down the street from me. It has the SM465 with the creeper, and a 351 V-6. The truck looks to be in good shape with the exception of some bad bondo, a couple of minor dings, and a couple of spots of rust. The truck has factory A/C, the V-6, manual trans, 3/4ton running gear, and power brakes. Does anyone have any recommendations on this truck, is this a rare rig? (never seen this setup before personally). What price would be a good asking price? Any inherent problems with the GMC V6's (have been reading up on the 6066gmctrucks.org site, and they sound like a pretty decent engine...parts availability an issue? What kind of mileage would you expect out of a truck with this setup? Thanks -Lee

05-17-2005, 11:22 AM	#2
70 shorty Where's my beer? Join Date: Oct 2004 Location: Glen Allen, VA Posts: 1,768	all I can add is what I've read from this site, and that's that the 351 V6 is definitely preferrable to the 305 V6. __________________ 70 C10, shortstep, .30 over 250,Hurst shifted 3 spd parts hauler. Holley 390, Clifford Intake, Header, ported cylinder head, unknown bigger cam. 79 Corvette L82, 4 spd, black, red interior, headers, flowmasters, and unkown bigger cam. '03 Grand Cherokee Laredo, 4.0 4x4 daily driver. 165K miles, and runs great '08 Tahoe LTZ 4x4 155K

05-17-2005, 11:34 AM	#3
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	Mileage is lousy, engine can't be killed. You've got to love a "truck" to want that combo. That being said, I'd be all over it, especially if it hasn't been hacked up. If you plans include yanking the engine/drivetrain in favor of something more "modern", look elsewhere. The 351 was not at all common in light duty pickups. But don't think its gold either, its a niche market at best for those old beasts and not many people find them desireable. __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

05-17-2005, 11:48 AM	#5
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	10 mpg or so, but you'll get it loaded or standing still . PM user Erl, he's got a V6 and knows a bunch about them __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all Last edited by CPNE; 05-17-2005 at 11:49 AM.

05-17-2005, 01:56 PM	#7
Dano69c10 Senior Member Join Date: Jan 2005 Location: Ontario, Kali Posts: 2,427	Check out this website, "6066gmcguy.org". There are v-6 info pages, and some performance upgrade pages. The v-6's he has on the site look way cool! Especially the magnum v-6. Love those valve covers! Dano http://www.6066gmcguy.org/305V6.htm http://www.6066gmcguy.org/351V6.htm http://www.6066gmcguy.org/performance.htm http://www.6066gmcguy.org/Jolly-351v6.htm http://www.6066gmcguy.org/Jolly-478v6.htm http://www.6066gmcguy.org/Jolly-401v6.htm __________________ '69 Fleet It ain't yours, if you didn't build it!

05-17-2005, 11:43 AM	#4
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	What does "lousy" equate to, if I end up with this truck, it might end up being the 25mile round trip for a commuter vehicle...not horrible, but I would rather it not take 6 gallons for the trip. Also, the site says there max RPM is around 3500, what would that put a max highway cruising speed at? (unsure of actual rear gearing). Thanks

05-17-2005, 11:57 AM	#6
724wdcopper graphic designer Join Date: May 2004 Location: Spokane, Washington Posts: 841	i wouldn't go looking for performance parts, either, but cool truck nonetheless. like the others said, impossible to kill, low revving, stump-pulling, torque monster, then you go and add the granny 4 spd, you could get out and walk up a hill faster, but it will do it at idle. not sure it would be a good 25 mile commuter, unless you're on surface streets. highway probably not the daily option for this combo. sounds like a cool rig, even has air, huh? right on!

05-17-2005, 03:19 PM	#8
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	I agree with all of the above. Drove a lot of trucks with the old V6. It will pull anything you can hook on, but don't expect to get there in a hurry. Highway driving kills them, the crank is huge and balance is horrible. The high nickel block will last for 500K miles, but the rotating mass will self-destruct when operation over 2,500 rpm is sustained. And they make a heck of a racket when you throw a rod. Someone in GMC corporate loved the engine, but the customers hated them. About the only tasks I would consider one for would be local deliveries, parade duty or boat anchor. Milage wasn't too bad, considering everything. Pickup with a 305 would get about 12. 2 ton with the 351 was 6 to 10. The 478 in a 5 ton got 4 to 8. I never drove a 401 in anything. Give me a straight six any day of the week. __________________ Fred There is no such thing as too much cam...just not enough engine.

05-17-2005, 07:39 PM	#9
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Just out of curiousity, and I am sure someone has asked, but with the search function being down.....since the engine is so torque happy, would it be possible to use the sm465 like a richmond 5 speed.....use the first lower gear (creeper) as first and put really high gears in the rear, like a set of 3.08 or maybe 2.8X....will this make it a little more highway friendly? I know on the richmond transmissions, they don't use overdrive, they have the same final drive ratio of 1:1, but have a much lower 1st gear to compensate (yes, aware the gear spacing on a 4 speed with a creeper will not be as ideal, just curious. (I have yet to grenade an engine....maybe 3 or 4 transmissions, but no engines....hoping to keep my record). Thanks

05-17-2005, 08:36 PM	#10
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	With the 351 in a pickup you could do it, and you still wouldn't need first gear to start. 3.08 gears with 28" tires would make about 2600 rpm at 70 mph. You could run all day and night like that. Be sure to visit Jolly's website, lots of good info. Adding either an HEI or Pertronix would help this engine. You should also be able to do a lot with the advance curves to help out your milage. And the Holley carb swap would help. It still won't be a speed demon, but should make a good, reliable driver for you. __________________ Fred There is no such thing as too much cam...just not enough engine.

05-17-2005, 11:25 PM	#11
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Also, if you can find one, it's possible to install one of the SM420's with a 4 speed auxillary overdrive transmission. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

05-18-2005, 01:58 AM	#12
chevymad Registered User Join Date: Jan 2001 Location: skamokawa, WA, USA Posts: 527	Tons of torque. I'd definately put as tall of gears as you can find in it. I drove a 66 305 v/6, 3spd once. Was foolin with the column shift and took off.. Only realized I was allready in 3d instead of first when I didnt have to shift.

05-18-2005, 03:24 AM	#13
rwgregory Registered User Join Date: Apr 2005 Location: Chula Vista, California Posts: 495	I'm on my second 3/4 ton GMC p/u w/305 V-6. Loved my '65 and have been kicking myself ever since I sold it. FYI, my '65 got 10/11 mpg loaded or empty w/4.56 rear gears & 33" tires. Only thing I ever did to it was split the exhaust into duals w/turbo mufflers. Gained quite a bit of upper end and it had a nice rumble to boot!! I would commute 22 miles each way, 5 days per week and take a 100/150 mile trip once or twice each month with it. Only problems were exhaust manifold bolts would loosen up and I would have to re-tighten them every 4/6 months, probably due to the majority or my driving being freeway. In a nutshell, I think these were great TRUCKS!! and I beg you not to butcher/modernize it with more modern/mundane drivetrain. Thanks for letting me rant, rwgregory __________________ rwgregory 67 GMC 2500 ,2w/d wide box 305 V-6, 4-speed

05-18-2005, 06:51 AM	#14
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	so again, just out of curiousity, i have visited the 6066 page, and saw the holley 500 2brl carb upgrade and the buick dist. upgrade. Has anyone out there tried to run a similar adaptor plate with either a revamped factory tbi, or a holley tbi? I have always been a big niche vehicle/engine fan, someone mentioned that the engine is poorly balanced, would it be possible during a rebuild to rebalance the crank/rods/pistons and see upwards of 5-6k redline? I can only assume that this would require valve spring and cam swaps at the sametime....possibly a port and polish would help a little. While the 6066 page is very informative, it doesn't seem like anyone has taken any steps to use the potential power of a "big block" v6.....and I have seen no mention of anyone that makes headers for this thing.....should I assume that means its a "you want 'em, you build 'em" kinda thing? Thanks

05-18-2005, 04:56 PM	#16
67-Cowboy Registered User Join Date: May 2005 Location: Salem, Oregon U. S. of A. Posts: 69	I'll put it like this I would dearly love to have another one ! They are the perfect Cowboy truck; stock they will pull and out pull any and everything, just put her in granny and load 250 bales on the trailer and she never misses a lick. With a threespeed tranny and a car third member running 2.7? gears you are running 55 miles an hour at a idle. With this ratio you get a little better gas milage too, we got like 18 on a road trip once with a new rear end. We sold our's to buy a newer truck because they aren't real easy to find parts for in certain parts of the country.



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05-18-2005, 08:03 PM	#18
724wdcopper graphic designer Join Date: May 2004 Location: Spokane, Washington Posts: 841	keep in mind also that if you're looking for a performance engine, the GMC V6 is significantly heavier than most small blocks. they were built as a truck engine with strength in mind, not weight savings for racing purposes. if you want a heavy performance engine, a BB chev would fit the bill better. if you fast rig, the V6's weight is going to be a hinderance. that's a lot of weight over the front end. but that said, i think engines that are a bit off the beaten 350 path are ultra cool. that's why i opted for an all aluminum buick 215 cid V8 for my 1929 chev streetrod. i'm still looking for parts (anyone have any), but that's the price you pay for individuality!

05-18-2005, 09:52 PM	#19
TP from Cntl PA Registered User Join Date: Apr 2003 Location: Central PA....In the Berg of Nisbet Posts: 790	IMO they were one of the best engines of their time for a "WORK" truck(AKA pickup)............I got a 305 V-6 in a '69 GMC 1-ton and it will pull like mad! Like these other guys said, they don't like RPM's...........But will take about everything else you can throw at them with good service intervals. I'd like to find a 3/4 ton with either a 305 or 351, 4spd, with 4x4...........Then bolt the gooseneck hitch in it and see how much weight you can get on it before you pull the ball out of the frame IMO, definitly more awesome than a SBC powered truck! __________________ '72 K-20 EFI'ed 250 Inline/4spd stake body, Farm Truck '71 C-20 Cummins Diesel Powered, In storage thanks to $5.00 diesel! '69 3500 GMC 305V-6/4spd, Still under reconstruction.......... Inlines Rule! 6 soldiers standing is better than 8 laying down!!!!!!!!

05-18-2005, 11:22 PM	#20
BobS Senior Member Join Date: May 2001 Location: West Central Minnesota Posts: 568	Not much to add that hasn't already been said. If the tranny is original it should be an SM-420. If the rest of the equipment is original it's a pretty rare combination. I'd love to have one of these with AC. If you buy it, please leave it original, there are plenty of other trucks around if you want to modify one. Bob __________________ V-6....only GMC Trucks have it! 62 GMC W5000 NAPCO-V6 65 GMC 2500 NAPCO Panel-V6 66 GMC 1000-V6 66 GMC 1500-V6 67 GMC K1500-SBC (originally a KM-V6) 68 GMC C1500-V6 68 GMC C1500-V6 68 GMC Suburban C2500 70 Chevy K20-SBC 71 Chevy C30 Longhorn-SBC 72 GMC Suburban C1500-BBC 72 Chevy C10-SBC 72 GMC C5500-ToroFlow Diesel

05-19-2005, 12:21 AM	#21
67_C-30 I have a radical idea! Join Date: Jan 2005 Location: Sweet Home Alabama! Posts: 6,513	As far as modding a V6 goes there is not a whole out there that I have found on Net, but I did see a Garrett Turbocharger installed on a 305E in a '66 GMC years ago. It was a unit off a Pontiac 301 Turbo Trans Am that used a suck through Q-jet carb. I saw this pre-Internet and I did not get pictures, but I've never forgotten about that thing. The guy did a very neat job with the plumbing and it actually looked like it could have come that way if you didn't know anything about them. He made a loop crossover pipe that went from manifold to manifold and then had a Y off that on the passenger side that went up to the turbo. He then had a bigger probably 3" pipe coming out the turbo going under the truck. That kind of turbo if you are not familiar bolts directly to the intake with a 3 bolt flange, and he made an adaptor for that and used the stock intake. He had the whole engine, including the intake side of the turbo, and the turbo carb adapter painted the factory V6 red. He had a big stock air cleaner on the Q jet that really covered it. I have included a picture of a 301 Pontiac Turbo engine and the turbo unit. Just imagine that set-up on a V6. Those type are dinosaurs also in respect to modern turbo units, but they made a sizeable gain on the 301's. The HP and TQ on a 301 Turbo is 210HP and 345 TQ compared to 150HP and 245TQ for a N/A engine, so it should have similiar effect on a GMC V6, since the 301 Poncho is a low revving engine with much more balancing issues than V6 has. The guy that built the truck claimed the engine was stock otherwise, and that the Turbo and 4bbl made it much more Torqueyer (if that's a word ) and it had much better overall power. He lit the tires up when he left the show, it had a very cool sound! I wish I had pics of it because it was really cool looking if nothing else! Attached Images __________________ '67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! Last edited by 67_C-30; 05-19-2005 at 12:23 AM.

05-19-2005, 11:04 AM	#22
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	would anyone happen to have an opinion as to the worth of a 3/4 ton, 351 V-6 GMC with (what I guess must have been) an SM420 (thought i read that the sm465 was picked up in 67...could be wrong), in a relatively stock form, and rust free? I know, I know, pictures, I am working on it.... :P Thanks

05-19-2005, 01:25 PM	#23
Dano69c10 Senior Member Join Date: Jan 2005 Location: Ontario, Kali Posts: 2,427	Man I wish I could buy that truck! Dano __________________ '69 Fleet It ain't yours, if you didn't build it!

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