1954 GMC 4WD Ideas

[69l46vert]

Greetings to All from here in Maine,

I am thinking of building my 54 GMC 101 into a 4wd using the stock frame. Not so much for hard core off roading but I do plan to have a snowplow on it for winter weather and want to have the capability to tow a mid sized trailer (3500 lbs max).

There doesn't seem to be a lot out here on the web about such a build. I do already happen to have a NP 205 mated to an SM435 that I thought I may be able to use. Does this seem like an ok starting point?
One aspect that I have no clue on yet is what to use for the steering. A recent post here on the Forum suggested pre 1986 Toyota axles. I'm not averse to this but might want something a little heavier. I don't want axles that are too wide and put the tires outside the fenders.

As far as my experience goes, I have done frame up rebuilds on a CJ5, a 4wd F250, and am just now finishing up 69 Corvette. All work done by myself including paint so I'm not totally green but these have all been stock rebuilds. I have not yet done any car/truck building that used parts from different vehicles. Everything I've done so far has been pre engineered so this aspect is completely new to me and it's a bit worrying. I do have a well equipped shop, welding and machining skills. (My job).

I'd appreciate any links or advice about a project of this type. What to avoid and what to look out for, Parts that might work for me and such things as that. Especially regarding the steering.

My plan is to gather some more parts for this project while I'm finishing the Corvette (est. July 2015) and jump right onto the 54. Thanks for any help or advice. Links very much appreciated too, Rick

Here's a pic that I'm using for inspiration

[ghettoluxury]

I personally would try to stick to something that bolts to the outside of the frame, just to keep as much engine space as possible. The radiator on these makes space up front very tight so using the traditional Saganaw box is not really a good option. This is going to mean that you are going to have to cut a section out of you inner fender for the box to sit in place and the steering shaft to pass through. Your next hurdle is going to be placement once the axle is in place and you know what plane you are working on.

I would probably start with a box from a 73-87 Chevy truck (this is assuming you are using a small block engine) then go from there. I can already see that the factory shock location is going to have to go. From this point (if the box was too big or there were other complications like leaf spring interference) I would look at some of the Toyota stuff. The truck boxs have the pitman arm facing to the rear of the truck and the FJ80 has it facing the front of the truck.

[OrrieG]

Take a look at this, I posted mine and some comments:
http://67-72chevytrucks.com/vboard/s...d.php?t=657042

Might also ask in the 4WD section. The AD frames kick in at the front so mounting the 74 or so box like I did might not have the same issue with the pitman arm. 73+ frames kicked so the arm was out of the way.

[69l46vert]

Thanks both of you for the advice. This steering business seems like it may be the biggest hurdle for me. I have a lot to learn about this part of the build plan.
Also, from OrrieG's linked thread, could someone explain CCP please? It sounds as if it must be a company that sells steering parts? Thanks for the help, Rick

[OrrieG]

http://www.classicperform.com/Chevy-Truck.htm#40

scroll down the left box to power steering and click.

[69l46vert]

Originally Posted by OrrieG

http://www.classicperform.com/Chevy-Truck.htm#40

scroll down the left box to power steering and click.

Wow, Some really good info there. Thank you for that link OrrieG. I'm going to study up on it.
Out back behind the barn I have a 4wd 72 GMC K2500 with P/S that I had already (tentatively) planned to use the motor, tranny, Tcase, column and pedals. Maybe it can donate some steering parts too. I sure do appreciate the information. This is getting less scary all the time! Thank You for taking the time to post the link, Rick

[octanejunkie]

I'mIm running a mid 80s Toyota pickup p/s box in the stock location on my '59 with a chevy van tilt column from the same era. Bought that kit from CPP several years ago, they no longer sell it though. The base of the p/s box is milled to fit to a bracket that installs inside the frame rail and the box sits onboard of the frame. I had to run rams horns exhaust to clear the steering box.

I recently installed a steering damper to take some of the bounce out of the steering (road feedback) from the 31" tires I'm running. It also dampens feeling and reaction a bit, but makes the truck feel safer at highway speed.

I can see this setup working quite well for a 4x4 application. The Ford truck crowd still uses the toyota p/s box, so kits and parts are probably still out there.

[69l46vert]

Originally Posted by octanejunkie

I'mIm running a mid 80s Toyota pickup p/s box in the stock location on my '59 with a chevy van tilt column from the same era. Bought that kit from CPP several years ago, they no longer sell it though. The base of the p/s box is milled to fit to a bracket that installs inside the frame rail and the box sits onboard of the frame. I had to run rams horns exhaust to clear the steering box.

I recently installed a steering damper to take some of the bounce out of the steering (road feedback) from the 31" tires I'm running. It also dampens feeling and reaction a bit, but makes the truck feel safer at highway speed.

I can see this setup working quite well for a 4x4 application. The Ford truck crowd still uses the toyota p/s box, so kits and parts are probably still out there.

Good tip on the toyota box OctaneJunkie. Thanks. Of course I had san 84 toyota here a few years ago and let it go. Wish I hadn't because it looks like I could use the axles and steering parts now. Thanks, Rick

[69l46vert]

Well I've got the motor, transmission and transfer case out of the 72 GMC. The tranny is a Saginaw Muncie SM465 and the transfer case is a New Process 205. They are married. All in good condition as I recently drove the old truck before it was disassembled.
And I have a line on an 85 Toyota 4WD for the axles and possibly some steering parts. The Toyota axles are 4.10:1 and have the added benefit of accepting 6 lug Chevy wheels so I'll probably look for a set.
No real work started yet but just gathering up the raw materials. Any comments or suggestions are always welcome. Thanks, Rick

[octanejunkie]

sounds like you'vyou're got a good plan.
4.10s with 265/75-16 are a great combo.
Grab the p/s box from the Toyota too.

[OrrieG]

4.10 might be a little steep unless you get tall tires. My 74 axles are 3.74 with auto trans. There are rpm calculators online that let you play with the variables; tranny ratio output (1.0 in this case), rearend ratio, tire height and rpm. you can input any three to find the 4th variable. Salt flat racers also add in frontage area, drag coefficient to determine horsepower to get certain speed. Not a big deal for the trucks, but been playing with it for my Chevelle make over.

[69l46vert]

Originally Posted by OrrieG

4.10 might be a little steep unless you get tall tires. My 74 axles are 3.74 with auto trans. There are rpm calculators online that let you play with the variables; tranny ratio output (1.0 in this case), rearend ratio, tire height and rpm. you can input any three to find the 4th variable. Salt flat racers also add in frontage area, drag coefficient to determine horsepower to get certain speed. Not a big deal for the trucks, but been playing with it for my Chevelle make over.

Thanks OrrieG, I tried one of the calculators and 4.10's at 2000 rpm with 31" tires gives 45 mph so I see what you mean. Not great for highway speeds. I really don't think I want anything larger than 31's either. Rick

[OrrieG]

For a while I ran a 1 ton axle with 4.56 and sm460. Would climb a tree but 235 six maxed out at 45 mph. Good for back wood, but getting there took some time!

[octanejunkie]

Originally Posted by 69l46vert

Thanks OrrieG, I tried one of the calculators and 4.10's at 2000 rpm with 31" tires gives 45 mph so I see what you mean. Not great for highway speeds. I really don't think I want anything larger than 31's either. Rick

4.10 is the "correct ratio" for 31" tires to get the best overall performance potential out of your engine assuming you are properly cammed (not too big) and have the the right stall (about 2200-2400) to match your cam.

The following chart assumes 1:1 ratio at 65 MPH



At 65 mph you will make 2890 RPM at 1:1, and with 0.7 OD ratio that drops to 2023 RPM. This configuration of tire and gear has been pretty much standard with Toyota in the pickup and 4runner line for a long time.

If you want to drop to 3.73 gears, you will likely not get the best 4x4 experience but it will be 10% more highway friendly. 3.42 will be 20% lower than 4.10 and not optimal for a 4x4.

[69l46vert]

Thanks OctaneJunkie. Some good info there. Probably won't be on the highway a lot. We really only have one highway here in Maine anyway. But even so, it looks like it will be ok with 4.10's. Probably not the best mileage but that's ok by me. Thanks, Rick

[69l46vert]

Still in the planning stages right now but gathering up some parts here and there.

My plan now is to shorten the Dana 60 rear and Dana HD44 front that I already have here in my possession. They have 4.10 gears. The idea is to wind up with an 8 lug 3/4 ton shorted 4wd AD.

An older gentleman had a 69 shortbed Chevy step side 8 lug 3/4 ton in my neighborhood when I was a boy and I always loved that truck. It was brand new and I have a vague memory of him telling me he had to wait a long time to get it.. I don't know if it came from the factory that way as I've never seen another one since. Anyone have any info on such a truck?

The WMS-WMS on these donor axles is about 70 inches. It looks like I need to take 5 inches off each side. Does this seem about right for an AD?

Trying to decide whether I should respline the existing axles or just buy new shorter ones. Even though I work in a machine shop we just don't have manual machines available or time for me to do it myself there so I'll be looking to get another shop to cut them if I go that route.

I would love to learn what shorter stock axles would work in this situation. Maybe something out of a different truck? Still haven't taken anything apart yet so I don't know the length of the existing ones. I don't mind buying new ones either.

Also toying with the idea of making the bed dump. I think it would be pretty cool to use a pto on the SM465 for this but maybe an electric pump would be more practical. Thanks for any input or comments, Rick