So I am collecting parts for my newly acquired 47 Chevy truck. It's complete minus engine and tranny, which I just found also - Big block Buick 455 backed by a th400. The rear is a GM posi and the front has already been stubbed with a Chevelle front clip. My question - that's going to be plenty of power to the rear. Currently there are leaf springs and I wonder if this should be converted to 4 link and coil overs, or if a stouter leaf setup would work as well. Either way, I will box out the frame and add cross members. Thoughts?
My first thought was on the chevelle frontend.... I think those are too wide for your truck. It might push those wheels out into the fenders. You don't need to convert it to 4 link, but if you're going to bag it you'd want to then. But there's nothing wrong with leaf springs in the rear, you could even go with the lowered rear leaf spring to clean it up a bit.
Thanks Chaddillac - the front actually fits prettty well. I still need to chop the front of the frame rails to get the inner fender panels and radiator support to fit. I saw in Craigslist some racing leaf springs for Chevy and wondered if that would be a way to go without major mods to the rear. Good to know I don't have to go 4 link yet. Although in the future I may bag it, but for now my goal is to get it on the road in a year or so.
Depends on how you want to drive it. triangulated chevelle/ monte rear would have the best of most worlds. Can't go wrong with leaf springs.
If you want "traditional" then leafs with slapper bars or a leaf-link is the way to go. Get a set of modern, wider springs; and don't use blocks to lower it. Keep the axle as close to the spring as possible.
Consider the truck-arm suspension from later Chevrolet trucks (60s-early 70s). Simple, strong, effective.
Your leaf springs are going to be plenty stout enough, what you want is ride control. I have had good luck mounting a pair of Air Shocks angled a little towards the front in front of the axle when I was looking for a low buck solution to wheel hop. You add air to control spring wrap. Unless I was building an all out dragster I wouldn't go the expense of a 4 link coil over setup. What you may consider though is a trailing arm setup like GM used through the '60s with coil springs. They work real well give you good ride control and are easy to set up. if at a later date you decide to go with bags its just a matter of replacing the coils with bags.
My dad has an 88 chevy pickup, I know the year is OT but...., first ran it with a BBC 454 with lots of HP and used the stock rear suspension...original leafs and nothing but. There wasn't any noticable spring wrap or hopping or bouncing in the rear when we lit it up. If I were you, I'd be using the stock springs that are in it, but I'd fabricate a torque arm...similar to the Camaro's. That'd be the easiest thing...it would eliminate the chance of spring wrap and help with traction. There's some nice examples of torque arms on the HAMB if you search. Believe me, traction, or lack of, will be the biggest issue with your motor/tranny combo in a truck. -Steve
PS. As for boxing and adding crossmembers to that frame...I wouldn't do it. They're made from pretty heavy gauge steel and are made to move and have a little wiggle room while carrying quite a bit of weight. If you decide to make a torque arm, you might add a crossmember up near the transmission to attach the arm to, but that's it. As long as you're using body mounts and softish style motor mounts, I can't see the extra HP causing you any problems. If we're talking about a race car with slicks that actually hooks up instead of just burning rubber off, then yes, you'd have to make the proper mods... And again, my dad's truck got driven like it was stolen...stock everything except the motor/trans and we never did any damage to the frame, crossmembers, body...nothin...
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