I have a question for the steering system gurus out there, and you know who you are.
A buddy of mine is building a '55 First, AD series 3/4 Ton panel truck project. He decided to go with the front suspension from an '81 Chevy C-20 3/4 Ton pick up as we don't think the MII kits would be strong enough for his purposes. Right now the project is still in the disassembly stages, and we figure he has 3 ways to go with this part of the build. One way is to machine the spacers for use between the '55 frame and the '81 crossmember, steering box, and idler arm like we've seen elsewhere online. Another way is to narrow the crossmember and try to use shorter tie rods to get the front end alignment right. And then I thought of a different idea. After narrowing the '81 crossmember, would it be possible to use a power rack & pinion steering system out of a later model sedan or something else on this project instead of trying to work out shorter tie rods? Would this be an option for use with the spacers between the '55 frame and the unaltered '81 crossmember?
This is a large panel truck with a 137" wheelbase (as it turns out, this is the same wheelbase as a late model Ford Expidition,) and it's based on a 1-Ton panel truck frame. The truck will use a Chevy 350/700R4 combo for power, and while it won't be a daily driver, it's being built to be driven often. It might see duty towing a flatbed trailer on occasion, and possibly a boat later on down the road, but mostly just for cruising around town, or the local highways. The panel will weigh somewhere in the 4200 - 4700 lb ballpark, depending on how crazy he goes with the interior accessories. We've done a little bit of looking online, and I've found the newer 4160lb Cadillacs and 4200 lb Dodge Magnums using R&P steering, so I'm thinking it might be possible, but I wanted to check with the gurus here at the board before I encouraged him to dig deeper for info. We have access to a full machine shop and a highly qualified machinist to run things, so slight modification of the ends of the rack or the C-20 suspension shouldn't pose a problem.
Basically, my questions are: is his truck too heavy for R&P steering? Just too durned big maybe? Any suggestions on a particular make/model of vehicle to look for as far as a donor rack is concerned?
As I said, the truck is still in the disassembly stage, and all that's left is pulling what's left of the stock suspension, and removing the body. He's got the '81 Chevy suspension sitting here, and is just making up his mind which way to go on its crossmember. Any help you could give us would be greatly appreciated.