Opinions requested on this 67 GMC...

[dogman88]

...I am thinking of purchasing a 67 GMC 3/4 ton 4WD. I had a 1969 GMC 1/2 a few years ago, so I'm not a stranger to these great trucks. This one is just a little out of my realm of expertise. It has a GMC V-6, which I have no experience with whatsoever. It's a 4 speed, and is geared to the gills (as my 69 was), but the owner mentioned a top speed of 55 MPH. The truck is in great condition, for a farm truck, and I am curious about a few things. Primarily would be gearing the truck (numerically lower) for higher top end speed. Or perhaps making up for the gearing with taller tires. If anyone has personal experience with any of this, I would love to hear your input. Also, not a real important point but this truck is "radio delete". Just wondering how many trucks without radios that you guys have seen. TIA for any help you guys can give.

[Robert1970C20rstbukt]

It's probably a 401 high torque V6. They'd turn out 237HP @ 4000RPM's and put out 372ft lbs of torque at only 1600RPMs! Pretty cool engine, I've never seen one though. I just know the specs on it.

[LUV2XCLR8]

6 SPEED MANUAL, WILL HELP TOP SPEED ISSUE

[1969 GMC]

that truck would be pretty cool! 305 V6, SM420 transmission, Rockwell T221 transfer case. Most likely 4.56 gears if the p/o says the max speed is 55. i am dying to see pics!

Radio deletes arent really that hard to come by, I bought mine for $10 and about the max I have seen is $20 for one.

[dogman88]

Thank you all for your input and for the welcome to the board. First off, I didn't take any pics when I went and looked at the truck, but really wish I had. I know I will be looking at this truck again soon, so I will try to get a few snaps then. I had a feeling that the gearing was around 4.56, and you guys are kinda confirming that. There wasn't an option list on the glove box door. The P/O didn't have any idea, and the truck doesn't run at the moment. I know that the truck doesn't need much to get running, as I talked to the last mechanic that did work on it and he knows the history of the truck. Big thanks to you, Moonlight, for the article and the chart. And as far as "granny gear" trannies, I had one too. You could pull the moon down with one if you could get a rope around it, heheh.

Just to let you guys know a little more about the truck, it's on a farm, and like I had mentioned before, was a farm truck all it's life (hauling grain and livestock). And of course they have the spare bolted up to the front of the truck (don't get much more "farmy" than that, heheh. But it has been well taken care of, much to my dismay of knowing how well farm equipment is cared for. Currently there is a ton of dirt on it, as it rests in a shed. It sits on split rim 8 bolt wheels which I will be looking to replace if I buy it. So if anyone knows what wheels will fit over those hubs sticking out, I'd appreciate info on that too. This is a base model truck, with no trim, or any real options inside and out. Once again, I appreciate any and all info I can get. Take it easy!!

[Longhorn Man]

First and formost...welcome to the forums. Lots of info here, and lots of deals to be had. Where do you call home?

As for the engine, it is most likely the GMC 305, but it could be the 351. most liklely 305 though. I think the 351 was a one ton option only.
Gearing...I have found that many people do not know what 5000 RPMs sound like. I have owned a 4.10 geared truck and it could go over 100 MPH. I have spoken to quite a few ppl with the exact same combo as that truck had, tell me that 55 was the max. My money says the farmer is scared to go any faster becouse it makes too much noise. A quick cheap yard sale/swap meet tach will prove/disprove this. My money also says it has 4.10 gears. GMC knew ppl took pick ups onto the freeway. That and the unreal low end torque that the V-6's put out makes higher gears (numericly lower) easy to do. All of the 305/automatic 1/2 ton trucks I've seen had 3.07's in them, and still pulled like a SOB. (including my SWB GMC...it's an ex-305 truck)

[dtlilly]

Welcome to the board. You can use any steel or aluminum 8 lug wheel from 60's through 90's on that truck. Sounds like a good purchase.

[1969 GMC]

Originally Posted by Longhorn Man

As for the engine, it is most likely the GMC 305, but it could be the 351. most liklely 305 though. I think the 351 was a one ton option only.

I remember Erl posting that the 351 was not available in 4x4's, but I think it was available in everything else. This '68 and older too, by '69 the 351 was gone from the lineup.

[krazy_texan]

actually the 351 was also a 3/4 ton option as my grandad had one, as far as those v6s go if you want a work horse of a truck i really would reccommend nothing else i have 2 of the 305s and one 351 all waiting rebuilds in my storage shed, i hope one day to put it in one in my truck.

[Yukon Jack]

Welcome to the board. Can't add too much to what has already been said. The front axle should be a closed knuckle Dana 44. When I got my 69 K20 it had a 307, 3 speed and 4.56 gears - really pushing it at 65 mph (without a tach).

[dogman88]

Thank you all again. If I can get the owner to give me a price, I will prolly pic it up. I think it will meet just what I'm wanting to do with it. Get back into a good 'ole truck, (I miss my 69 GMC), and have plenty of tug for my 5th wheel. BTW, I'm in Northeast Kansas, for those that were curious. When I do get around to getting it, I'll try to get pics up. It really is in good shape and think you guys will appreciate such a find. I appreciate the warm welcome from all of you. Now back to searching the board, heheh.

[Canadian694x4]

Welcome To The Board!!!

[Erl]

The 351 V6 was an option in 67 and 68 for the 1/2 and 3/4 ton 2WD. The 305E V6 was the only V6 choice for the 4x4 in 67 thru 69. The rear end gear ratio was 4.56 with no optional ratio. 55 MPH top speed sounds about right. It makes the truck almost unusable on many roads. I changed my ratio to 3.73 with 33 inch tires and can keep up with traffic now. I recommend replacing the carb with the Holley 500 to get more power. Oh, power steering is a must if you plan on driving much. I have done the conversion and can give you some help.

[dogman88]

Erl, thanks for your input. The carb change and installing gears wouldn't be a problem, but I have a couple of questions for you. What kind of gears (e.g. Richmond?) did you install and where did you get them? Did the 33" tires fit with no mods? And, I would REALLY appreciate the info on the power steering install. I used to strongarm the 69 I had and don't feel like working out again, LOL. Thanks for the info. And thank you Canadian for the welcome.

[Longhorn Man]

If you get this, I may be able to get you power steering parts, there's been a couple v6 trucks show up in a local yard again.

[Erl]

The carb info is on Jolley's 60-66 GMC page. A Holley 500 and a adapter bracket are listed and can be purchase from JEGS. You can use a 5/16 by 18 inch brake line for the fuel line instead of what he shows. It was the original style and looks good. I bought the gears from Randy's R & P. You will need a new carrier to go to a 3.73 or 3.43. I went ahead and got the posi unit. I have 16 inch factory rims with the old time big lug mud grips that are about 33 inch in height. They have never rubbed, but I mainly travel on paved roads. Longhorn Man is right, you will need the pulleys and pump bracket from a 305V6. A 69-72 4x4 steering box and standard hoses are the main components (check with Teeitup). I also have the part numbers for the required new drag link. Modifying the frame is a little tricky, but I can help you with that.

[BobS]

Longhorn Man, Are those V-6 parts still available? I'm looking for PS pump brackets and pulleys.

Bob