The Stovebolt Site Forums The Parking Lot Big Bolts '66 GMC Frankenproject

Good morning y'all!

I'm relatively new to the "Bolts" forum but I've been employed in the Truck and Trailer industry all my life. I really enjoy reading about your projects as well (I owned a '49 Chevy two ton and drove it everyday back about 30 years ago).

I've been dreaming of building a super heavy '60-'66 Chevy/GMC one ton since high school and have been holding on to a sketch I did back then as my incentive to finally get it done (some 35 years later!). Basically, my plan is to stuff a Big Bolt drive train into a One Ton Dually just because it would be something different to do (I hate the typical 350 SBC with all the billet that we see at all the car shows).

I've now acquired a '66 GMC 3/4 ton fleetside (body is in great shape) that I'm converting to include more modern front disc brake/spindle setups as well as a matching wide Dana 70HD rear end which I intend to modify for disc brakes as well. I plan on grafting the same series stepside fenders into the fleet side bed to create a "dually" bed.

Now for the tough part that I'm hoping y'all can help me with. I am acquiring or have acquired several of the GMC V-6 engines of the era with the goal of installing a 478" V-6 in place of the original 305 V-6. In doing so I plan on installing a 5 speed overdrive main box out of a Vietnam era 2.5 ton truck along with a 3 (or preferably 4) speed aux trans.

I've located a source for the 5 speed main box. I'm hoping one of you folks out there might have and be willing to part with the Aux Trans shifter brackets, floor pan, shifter and linkage for a 60-'66 Chevy/GMC truck cab. I think I could manage to fab up the shifter linkage on the chassis but it would be nice to see photos of or acquire those parts as well. Obviously, I'd be interested in speaking with one of you if you have an Overdrive Aux Trans for sale as well.

I am anxious to learn from the experiences y'all have accumulated and I'll be glad to help wherever I might be able.

Thanks,

Steven

Steven
Welcome to the Stove Bolt group.
Sounds like an interesting project you are taking on and you are very informed on what you want to do.
The 437 V-6 is a rare engine and would be a great conversation piece at any Car/Truck get together.
I have a 637 V-8 that is supposed to be the same design as your V-6, only a couple more cylinders.
Some body that knows more than me will be chiming in here soon and I'll be watching this topic to learn a little more about these big blocks.

Don

Don,

Thanks for your interest. I assume the 637 you have is in your GMC ladder truck. Am I correct? I like the looks of that rig and have a fondness for fire apparatus (after 10 years as a volunteer fireman and EMT many years ago).

I'm sure it was a typo but to correct it for anyone else that may read this, my V-6 engine is a 478" displacement.

I'm also interested in your Plymouth Belvedere. My folks first car when they got married was, I believe a '53? which I think they said whas Salmon and Black colored. I'd love to see a photo of that car, if you don't mind.

Thanks,

Steven

Steven
Just got home and put the 9500 ladder truck away in the barn after a charity event for AMVETS.
The 54 Plymonth Belvedere, I traded a 64 T-Bird in on it when I was 19, about 1975. Should have kelp the T-Bird and some other cars I've had in the past.
Hind sight is 20/20, and all we need to do, is look to the future.
Make the best desisions we can make at any given time.
And don't look back.

Don

Steven, the Stove Bolt reunion in KC is well worth going to!
You will meet some amazing people and you will learn a lot on a face to face meet.

I had a 478 in a Chevy Tilt Cab and the one thing I remember is it was governed low, I think at 3500 rpm and that got terrible gas mileage...maybe 5 mpg. They run like a diesel, high torque at very low rpm.

Welcome and good luck with your project!

Mike B

I've kinda thought of the same type of deal myself, but in interest of wanting it to be able to tow and haul I'd rather go with a big truck to start with, or put the sheet metal on a big truck frame. It would then be necessary to have the big truck style front fenders that are wider. My plan was to put a pickup bed though modified on it. The problem with a lighter truck and having all the big truck stuff on it, is your getting close to maxing out its payload with the heavier parts, kinda makes it not usefull for much else but shows.

You're right about the low speed engine....a lot of the reason I'm planning on the Overdrive trans set up (besides the cool factor).....and you're correct about the weight. So heavier jobs will require use of a gooseneck style trailer to take most of the vertical load off the truck suspension.

I'm also contemplating installing the medium duty front sheet metal. There are two different flare widths available on the front fenders. The narrower of the two should look good and allow me to install full length running boards between the front and rear fenders.

Thanks for the feedback!

Steven

Welcome to the "Bolt"!! you've had 35-years of doin' your homework,so now you're gettin' down ta business! AWESOME PROJECT!! PLEASE!! Some pics,and keep us posted!! Sent a P.M.

I'll second that.
When I started my project truck I already had a 1 ton running and driving I could have put my chosen engine and transmission in. But I realized/understood that I'd then be building a truck much more capable than a 1 ton truck, and it'd weigh a tad more to start with.
The better plan I thought (and still do) was to find a 2 ton which provides a heavier frame more in line with the capabilities of the rest of the truck I wanted to build. In the end it's not much bigger and only a tad longer than the 1 ton, but a much better matched or proportioned truck.

I have some experience with the opposite of that as well. I bought a 1961 F350 with a Detroit Diesel 6V53T swapped into it. This would be similar size and weight to the 478 V6 you're considering also putting into a 1 ton. The truck had a 10 speed Roadranger and I swapped larger axles/brakes under it. In the end the VIN tag in the truck said it was rated for 10,000 lb, and it weighed in just over that with a half tank of fuel and nothing else. It was/is a nice truck, but it's not very well proportioned, the frame looks quite spindly for what the truck is and can do.
https://picasaweb.google.com/118082...esel6V53T?authuser=0&feat=directlink

For what you want it sounds to me like you'll be better off starting with a small/short version of whatever truck you can find that actually came with your chosen engine under the hood.

Grigg