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rear suspension upgrade

5K views 4 replies 4 participants last post by  Sin Wagon 
#1 ·
HI: I am new to this site, and am currently building a 1957 Plymouth Belvedere. (Pics are posted on this site) I am making this a modern driver with an LS1, disc brakes, power steering etc. As you can see the front is good, but now I need to address the rear suspension. I'd like to at a minmum add a sway bar, maybe upgrade the leaf springs (any reccomendations on what will fit??). I also have a panhard bar laying around from a 3rd gen trans am- could that be made to fit easily? Is this a good or bad idea? The car has the original 1957 rear end. The goal is to make a modern driver out of this. not a race car. I want good smooth supension and decent handling. The car will be a "family car" so I need it safe and reliable. Any suggestions on what I should do to improve the back suspension of the car would be greatly appreciated! Thanks!!
 
#2 ·
A sway bar would be a good addition. Most station wagons came with them. See if you can find a replacement bar for a '57 Belvedere wagon...
DON'T put a panhard bar on a leaf spring suspension. Entirely unnecessary (the springs locate the rear end) and all you will be doing is inducing bind into the suspension travel. The leaf springs, basically, go straight up and down during suspension travel. A panhard bar travels in an arch. If you put a panhard bar on that is too short or to long it will try to move the rear end from side to side as the suspension cycles... Not what you want it to do... Let the leafs do what they are designed to do.
Rebuilding the leaf spring pack with new bushings (polyurethane) and some teflon buttons between the leafs would add a lot of performance and a good set of shocks would get you a decent handling, safe, car.
Mark
 
#3 ·
Astro again is correct........ I would also add that if you are concerned with spring wrap that you can utilize something like the "Wishbone" from Thomas Racing Compnents out of houston. That is a cool piece.
 
#4 ·
Wow, thank you for the info!

Yeah, I am concerned about spring performance as these are big, old springs on a big, old car. Noted on the panhard... I realize spring rate doesn't change, and at the least I will upgrade to some urethane bushings. Thank you for the info regarding the station wagon! I wasn't sure where I'd find one that would fit properly.
 
#5 ·
if you are having any spring sag in the rear you could purchase a new set or have your's re-arched to eliminate this problem, your local yellow pages should be able to direct you to someone locally that provides this service...if you wanted to spend a little more money a 4 link and coil over would be a great choice as well....virtually eliminate all axle wrap what so ever....
 
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