I am in the process of rebuilding my differential plus the trailing arms (bearings + bushings), all u-joints, etc, etc. - I really want to dump my tired 9 leaf rear spring for a monoleaf setup such as VBP, Van Steel, TWA or any others that might be out there.

My ride is a cruiser on mostly weekends - easy riding

It looks like Van Steel has a good reputation and VBP may be has a hard time fullfilling orders? How about TWA?

Thanks!

 

Been a while since I used either, but when I was buying parts VB&P and Van Steel were the tops. I would have no problems ordering from Van. TWA I know nothing about


Edit: wow VB&P closed. Well I still would have no problem ordering from Van. Heck at this point I'd go to coil-overs & dump the the whole transverse spring.

 

I just completed the same task about a month ago as you're about to undertake, along with the front suspension. I went with the 315lb Fiberglass Rear Spring from ZIP Corvette. I chose it mainly to save a few $.

 

I bought my 360 composite to replace my 7 leaf OEM gymkhana spring for my 78 L-82 4 speed in 1986 from VBP and it has been perfect all these years.

Your 9 leaf base suspension transverse spring should be replaced with a 300-315 lbs composite spring. Composite spring rates are different than a steel spring rate and are not one to one. The rebound/compression of a composite spring is different than a steel spring so do not assume a 1:1 spring rate comparison. Your 1979 base spring rate is 192 lbs/in. The 300 lbs composite will not only ride MUCH better, with a quicker reaction time over bumps and comes with a handling improvement, but it only will weigh 8 lbs versus 50 lbs for the steel spring and will never wear out like a steel spring.

My gymkhana steel OEM tranverse spring was rated 292/lbs in 1978 and i replaced it with the 360 composite which made a BIG improvement in ride, steering response and handling....The 360 composite rides much more compliantly that the OEM steel 292lbs spring. Make sure that you use a top quality shock like Bilsteins with a composite, otherwise the ride may be too bouncy in the rear with a standard shock. I use Bilstein Sports in back with the 360 composite and Bilstein HD's in front with the Sport 550lbs coils...I would recommend Bilstein Heavy duties at all 4 corners for your base suspension C3

 

Thanks tviscomi, that is the one I am looking at as well. Have you had a chance to ride on that new spring? What's your impression? Did you upgrade the shocks as well?

 

Yes, I've probably put at least 300 miles on my 78 since the completion of my overhaul. As far as ride performance, it seems fine for me. Hard to compare a before and after due to the fact that the entire suspension was shot prior to upgrading. In regards to shocks, I went with Delco on front & rear in order to keep my costs down. This project initially started out as just shock and leaf-spring replacement, but once I put it up on the lift I noticed 1" play in rear diff, TA bushings fried and well once I was in that deep I decided to rip out the front too. Needless to say I "blew" through my paint budget, but I am now have the assurance of a safe driving car.

 

I purchased a 320# spring from Van Steel. It rides very well. But I have Koni shocks that might be contributing to the ride quality. May I suggest getting a shorter spring if wider tires are in your future, The spring will rub the inside of the tire unless running bigger diameter wheels and tires.


Craig