Hmm. I can't tell you how I've DONE it because I haven't finished yet...
But since all the big parts are inside the same shop I can tell you my plan. I want to be able to pull a 10,000 pound load across Wyoming where the speed limit is 75 and there are lots of hills to go up and down. I want it to drive easy and comfortable, meaning power steering and more than adequate brakes.
The rear axle has 3.42 gears, which is the key to higher speed for mine. I estimate about 2800 RPM at 75 with 265/75-16's. My motor is a Cadillac 500 and the transmission is a TH400. 2800 is near the top of the torque band for the 500 and I think gives me more then enough pulling power for up to 10,000 pounds hooked to the hitch.
As for brakes, it took me a while to settle on the right plan for that part. The rear axle is a GM 14-bolt (with 3.42 gears) and it has large drum brakes. I've measured them but have forgotten the size. I've considered swapping to disks brakes since they are available for this axle, and may end up doing so before I'm done. The rear brakes were the easy part.
For the front I'm using a '72 Chevy C20 IFS complete with disks and power steering. This is the same stuff Chevy put under a single wheel 1-ton and my particular setup came from a big block truck. I spent a lot of time considering disk brakes on the original axle, but after looking at several trucks with the same IFS and talking to the owners I concluded this was the best route for me.
Today the big parts are scattered around three stalls. The bare frame has the rear axle and suspension in place, and most the un-needed stuff removed from the front. The motor is on the floor ten feet in front of the truck, and the IFS is on blocks in another stall with the cab in between.
I'm only managing 8 to 10 hours a month on the project so it may be some years before I get to drive it... Aside from basic maintance on my other stuff this is the only project I'm actually working on these days. Pictures and more details are on my web site at
Maxwell Garage Service Truck.
