V6 Big Block??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72gmcshorty · 02-24-2009, 09:24 AM

HUH??

http://vancouver.en.craigslist.ca/cto/1047571731.html

**Stocker** · 02-24-2009, 09:55 AM

Yup! http://www.6066gmcguy.org/305V6.htm

theyammieguy · 02-24-2009, 11:45 AM

My boss has one in his 64 GMC.

ChevLoRay · 02-24-2009, 11:51 AM

Stock engine for '67. In '68, they didn't offer the V-6 (as I believe).

djracer · 02-24-2009, 11:55 AM

I worked as a parsts guy in high school and I had a deer in the headlights look the first time someone asked for parts for a 305 v6! The pistons are the size of coffee cans!

Critter · 02-24-2009, 12:36 PM

I'm familiar with the GMC 305 V6, but is it correct to call it a "Big Block"?

old Chevy guy · 02-24-2009, 12:36 PM

I had a few trucks with that motor and that was always the joke "Bike Block 6 cylinder" I had more than a few people walk up while I was checking the oil in my 67 GMC and ask if it was a 396.If you've never seen one their huge! Not to speedy but if it hooks up to the ground it will pull your house down!

Bino · 02-24-2009, 02:13 PM

Quote:

Originally Posted by Critter

I'm familiar with the GMC 305 V6, but is it correct to call it a "Big Block"?

Seems like it would make sense... the 4.3L V6 is a small block 350 minus 2 cylinders. Which would make the 4.3L the small block V6 (let's pretend the 2.8L didn't exist for the moment). The "big block" and "small block" designation is wholely based upon the physical size of the block, and the 305 V6 is physically much larger than the 4.3L and still manufactured by GM... I think it all works...

Longhorn Man · 02-24-2009, 05:04 PM

no, it is not, and never was a big block.
It is the GMC V6. The only style V6 they made. You can't call an orange an apple.
They were in 67 - 69 GMC trucks, never in chevy. The VIN on a GMC will stard with CM or KM if it is an original V6 motor. A coulple 305s, and a 351 was offered.

mark 68 · 02-25-2009, 01:14 AM

Anybody ever try to hotrod one of these?

OrangeCrush1970 · 02-25-2009, 10:55 AM

GMC's RULE!

R.L. · 02-25-2009, 11:37 AM

I wonder why they were discontinued.

djracer · 02-25-2009, 12:30 PM

might be good for a stock class pulling truck!

primered_junk · 02-25-2009, 04:11 PM

A guy at work has one in a c-20 he did a dually conversion on, he built a set of headers for it, made his own flanges and all, dualed out through old school cherry bombs. The thing sounds like a WWII air craft, and will pull the fur off of king kong. It gets lousy mileage, and is a total dog when it's not loaded, but has tons of cool factor.

100%Chevy · 02-25-2009, 10:25 PM

I have a 351-C.Bigger than my 454.And heavier!It came from a 71 dump truck.
Plan to put it in my 64 GMC,1/2 ton truck.
Mike.

spinning wheels · 02-25-2009, 10:58 PM

I have seen early 60s trucks with this engine.
The valve covers sure look a lot like 348/409 V8 valve covers.
Just wondering if the 305 is a 348 minus two pistons?
The 348 was made at the Canadian plant and was originally designed for truck use only.
The 409 was originally a stroked version of the 348.

68C15 · 02-25-2009, 11:09 PM

Quote:

Originally Posted by spinning wheels

Just wondering if the 305 is a 348 minus two pistons?

nope, it was a completely different mill all it's own.

Longhorn Man · 02-25-2009, 11:13 PM

it is nothing like any other engine before, nor since.
I find it interesting that some of the methods used back then to make this a less often serviced engine have been put back into use over the last 10 years or so.

old Chevy guy · 02-25-2009, 11:18 PM

Quote:

Originally Posted by djracer

might be good for a stock class pulling truck!

Funny you say that,when I was a kid of 16[a lot longer ago than I want to admit] I went to a fair with a buddy of mine and saw my first 4 wheel drive pull. There were no crazy modified monster trucks just stock 4 x 4 daily drivers.They had a weight transfer sled they were pulling.There were lots of new and almost new rigs and we watched a few guys blow driveshafts,break axels,shred diffs and smoke some auto tranys and standard clutches.When it was all done the truck that out lasted ,outdragged and outperformed all the trucks there was a 60 3/4 ton beat up and rusty GMC with that 305 V6 in it,driven by a guy that must of been 75 if he was a day! That was back in 1980.

*72lb4x4* · 02-25-2009, 11:55 PM

The mad (not) bomber said: "I find it interesting that some of the methods used back then to make this a less often serviced engine have been put back into use over the last 10 years or so."

Sounds interesting... Details? Link to info?

(I finally found what the TSA quote meant so I couldn't resist.)

Longhorn Man · 02-26-2009, 12:00 AM

LOL!!!
The main one that comes tomind (haven't read about the V6 motors in years) they placed the spark plugs on the top side of the heads, by the intake ports, instead of on the bottom byt the exhaust. They did this so the plug wire would be shorter. A shorter wire is less sensitive toresistance built up from age, and physicly has less rubber to get damaged. On top of all that, pulling them away from the exhaust makes them last longer since there is that much less heat to damage them.
These are all reasons why they now have coil on plug set ups on so many engines.

old Chevy guy · 02-26-2009, 12:49 AM

Not only that but when you go thru big puddles the wires dont get wet.

(I finally found what the TSA quote meant so I couldn't resist.)[/QUOTE]

I've been wondering what that meant could you enlighten me?

Longhorn Man · 02-26-2009, 01:02 AM

click on the Mike and andy's insane road trip link in my siggy... it's a long read, but lotsa funny stuff

*72lb4x4* · 02-26-2009, 01:11 AM

BTW: I forgot to mention the TSA thing was funny as well, you know. Nobody has a sense of humor these days, especially at the airport!

Go here http://67-72chevytrucks.com/ and scroll down... Hopefully it will work.

Hmm... I thought the idea behind one coil per plug was to reduce the problem of the coil "recovering" from the last time it's plug fired. Let's see if I remember... A 4 stroke engine fires each cylinder once every other revolution, so on a V8 a single coil system has to fire, well, quite often. A one coil/cyl system only has to fire a particular coil 1/8 as many times, so the voltage on the coil has much more time to build up.

I also thought it had to do more with distributors going away and crank sensors, but all this new stuff is just fuzzy ideas in my mind.

Plugs on the top of the head sounds hemiish, where if I recall, the plug is between the valves. Moving the fire toward the intake valve seems a good idea since the exhaust area would have a less combustible mixture.

Plug wires are always just a problem waiting to happen...

Can you tell I've been into the hops (long winded)? (Crap, couldn't find a beer smiley)

*72lb4x4* · 02-26-2009, 01:13 AM

Maybe I can make a sig and sort of quote with: Mike, don't stick your finger in that! Or Hey Mike, what's that straw there on the trailer?? Let's see... Yuck!!

02-24-2009, 09:24 AM	#1
72gmcshorty Registered User Join Date: Jul 2001 Location: North Delta, British Columbia Posts: 1,344	V6 Big Block??? HUH?? http://vancouver.en.craigslist.ca/cto/1047571731.html __________________ 1992 Gmc 2wd 1972 Chevy Blazer 2wd

02-24-2009, 09:55 AM	#2
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,722	Re: V6 Big Block??? Yup! http://www.6066gmcguy.org/305V6.htm __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

02-24-2009, 11:45 AM	#3
theyammieguy accepting donations Join Date: Oct 2008 Location: houston tx Posts: 521	Re: V6 Big Block??? My boss has one in his 64 GMC. __________________ 1999 Yamaha roadstar 1600 chop. (in progress.) See my builds here>http://s113.photobucket.com/albums/n238/nickrp_2006/ "Ya'll can go to hell, I'm going to Texas." David Crockett

02-24-2009, 11:51 AM	#4
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: V6 Big Block??? Stock engine for '67. In '68, they didn't offer the V-6 (as I believe). __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

02-24-2009, 11:55 AM	#5
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,892	Re: V6 Big Block??? I worked as a parsts guy in high school and I had a deer in the headlights look the first time someone asked for parts for a 305 v6! The pistons are the size of coffee cans! __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

02-24-2009, 12:36 PM	#6
Critter Future TOTM Winner Join Date: Aug 2006 Location: Bulverde, TX Posts: 2,692	Re: V6 Big Block??? I'm familiar with the GMC 305 V6, but is it correct to call it a "Big Block"? __________________ 72 Chevy CST K5 HIGHLANDER BLAZER Getting a 6.0,NV4500,NP205,14BFF (Currently laying all over the place in little pieces) 72 Chevy swb step-side "LS" 6.0 Here's a build thread of sorts 2002 HD2500 Crew Cab, 8.1L Allison 4x4 Daily Driver Check it out www.lsdyno.com

02-24-2009, 12:36 PM	#7
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: V6 Big Block??? I had a few trucks with that motor and that was always the joke "Bike Block 6 cylinder" I had more than a few people walk up while I was checking the oil in my 67 GMC and ask if it was a 396.If you've never seen one their huge! Not to speedy but if it hooks up to the ground it will pull your house down!

02-24-2009, 05:04 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: V6 Big Block??? no, it is not, and never was a big block. It is the GMC V6. The only style V6 they made. You can't call an orange an apple. They were in 67 - 69 GMC trucks, never in chevy. The VIN on a GMC will stard with CM or KM if it is an original V6 motor. A coulple 305s, and a 351 was offered.

02-25-2009, 01:14 AM	#10
mark 68 Registered User Join Date: Nov 2008 Location: texas Posts: 84	Re: V6 Big Block??? Anybody ever try to hotrod one of these?

02-25-2009, 10:55 AM	#11
OrangeCrush1970 Registered User Join Date: Jun 2007 Location: Smyrna, GA Posts: 709	Re: V6 Big Block??? GMC's RULE! __________________ *Rottenwood Garage* 1970...71...72 C1500 aka Orange aka Sideshow Bob 540 BB Straub Roller Cam, AFR Magnums, XP 950, TKO 600 2 Tons of Fun

02-25-2009, 11:37 AM	#12
R.L. Registered User Join Date: Sep 2008 Location: Mobile, Al. Posts: 687	Re: V6 Big Block??? I wonder why they were discontinued.

02-25-2009, 12:30 PM	#13
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,892	Re: V6 Big Block??? might be good for a stock class pulling truck! __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

02-25-2009, 04:11 PM	#14
primered_junk ASE master tech/machinist Join Date: May 2008 Location: Blue Mound Texas Posts: 303	Re: V6 Big Block??? A guy at work has one in a c-20 he did a dually conversion on, he built a set of headers for it, made his own flanges and all, dualed out through old school cherry bombs. The thing sounds like a WWII air craft, and will pull the fur off of king kong. It gets lousy mileage, and is a total dog when it's not loaded, but has tons of cool factor. __________________ "I sit here and I pray in my broken down Chevrolet....."

02-25-2009, 10:25 PM	#15
100%Chevy Registered User Join Date: Jun 2008 Location: Moss Point,Ms. Posts: 1,439	Re: V6 Big Block??? I have a 351-C.Bigger than my 454.And heavier!It came from a 71 dump truck. Plan to put it in my 64 GMC,1/2 ton truck. Mike.

02-25-2009, 10:58 PM	#16
spinning wheels Registered User Join Date: Sep 2001 Location: Hacienda Heights, California USA Posts: 474	Re: V6 Big Block??? I have seen early 60s trucks with this engine. The valve covers sure look a lot like 348/409 V8 valve covers. Just wondering if the 305 is a 348 minus two pistons? The 348 was made at the Canadian plant and was originally designed for truck use only. The 409 was originally a stroked version of the 348. __________________ '72 GMC custom camper 350/350 Last edited by spinning wheels; 02-25-2009 at 11:01 PM.



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02-25-2009, 11:13 PM	#18
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: V6 Big Block??? it is nothing like any other engine before, nor since. I find it interesting that some of the methods used back then to make this a less often serviced engine have been put back into use over the last 10 years or so.

02-25-2009, 11:55 PM	#20
72lb4x4 Account Suspended Join Date: Jul 2006 Location: DFW Posts: 1,427	Re: V6 Big Block??? The mad (not) bomber said: "I find it interesting that some of the methods used back then to make this a less often serviced engine have been put back into use over the last 10 years or so." Sounds interesting... Details? Link to info? (I finally found what the TSA quote meant so I couldn't resist.)

02-26-2009, 12:00 AM	#21
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: V6 Big Block??? LOL!!! The main one that comes tomind (haven't read about the V6 motors in years) they placed the spark plugs on the top side of the heads, by the intake ports, instead of on the bottom byt the exhaust. They did this so the plug wire would be shorter. A shorter wire is less sensitive toresistance built up from age, and physicly has less rubber to get damaged. On top of all that, pulling them away from the exhaust makes them last longer since there is that much less heat to damage them. These are all reasons why they now have coil on plug set ups on so many engines.

02-26-2009, 12:49 AM	#22
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: V6 Big Block??? Not only that but when you go thru big puddles the wires dont get wet. (I finally found what the TSA quote meant so I couldn't resist.)[/QUOTE] I've been wondering what that meant could you enlighten me?

02-26-2009, 01:02 AM	#23
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: V6 Big Block??? click on the Mike and andy's insane road trip link in my siggy... it's a long read, but lotsa funny stuff

02-26-2009, 01:11 AM	#24
72lb4x4 Account Suspended Join Date: Jul 2006 Location: DFW Posts: 1,427	Re: V6 Big Block??? BTW: I forgot to mention the TSA thing was funny as well, you know. Nobody has a sense of humor these days, especially at the airport! Go here http://67-72chevytrucks.com/ and scroll down... Hopefully it will work. Hmm... I thought the idea behind one coil per plug was to reduce the problem of the coil "recovering" from the last time it's plug fired. Let's see if I remember... A 4 stroke engine fires each cylinder once every other revolution, so on a V8 a single coil system has to fire, well, quite often. A one coil/cyl system only has to fire a particular coil 1/8 as many times, so the voltage on the coil has much more time to build up. I also thought it had to do more with distributors going away and crank sensors, but all this new stuff is just fuzzy ideas in my mind. Plugs on the top of the head sounds hemiish, where if I recall, the plug is between the valves. Moving the fire toward the intake valve seems a good idea since the exhaust area would have a less combustible mixture. Plug wires are always just a problem waiting to happen... Can you tell I've been into the hops (long winded)? (Crap, couldn't find a beer smiley)

02-26-2009, 01:13 AM	#25
72lb4x4 Account Suspended Join Date: Jul 2006 Location: DFW Posts: 1,427	Re: V6 Big Block??? Maybe I can make a sig and sort of quote with: Mike, don't stick your finger in that! Or Hey Mike, what's that straw there on the trailer?? Let's see... Yuck!! Last edited by 72lb4x4; 02-26-2009 at 01:17 AM.

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