Composite rear spring choice
Thread Starter
Instructor
Joined: Mar 2011
Posts: 127
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Composite rear spring choice
I'm in the middle of a complete body-off rebuild of my 70' 454. The car is being built specific for the Copperstate 1000 rally in April. Ride is important so I am contemplating a composite rear mono leaf spring. I've read older posts stating that the springs can cause the car to sit high in the rear. Different things with different makers. I don't want to go through the drill of trying longer bolts, etc. I talked to a sales guy at Zips and he was not aware of this problem. They sell the former TRW spring which seems to be the worst offender according to some of the posts here. The Hyperco seems to be the spring with the least of the problems. Have things changed? Do I stick with my old 9 leaf and call it a day?
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
for reference, this is a 74 with a VB&P 360# rear and 550# fronts. The VBP kit comes with 8inch bolts and this is set near the end of the bolt.
It looks higher in the front but that is because of the camera angle. It sits a tad lower in front than back.
It looks higher in the front but that is because of the camera angle. It sits a tad lower in front than back.
Drifting
Joined: Jul 2007
Posts: 1,889
Likes: 23
From: Kansas
Yes Sir; I used the VB&P rear 330 # Composite & the 460 # front, Stock 1982 front sway bar, which I think is 1.25 inch, & the 9/16 G. M. stock rear. The rear spring with the 8" bolts, sitting the nuts at 1 1/2 " from the ends of the bolts to the bottom of the nuts. The front springs are bigger round, than stock & 3/4 " shorter than the stock springs, & are the same size at both ends of the spring. Bilsteins schocks all the way around, It doesn't squat when you take off, but is not harsh riding at all.. I also have Aluminiun upper A-arms, which have Rulon bushings, & all of supension has been rebuilt. Have a new Borg steering kit on my Dinning room table, will install as soon as it warms up. I had no height issues. Have a ball, on the upcoming Run. Gene
Drifting
Joined: Mar 2011
Posts: 1,886
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For a comfortable cruiser, keep the front springs stock and change the rear to a Hyperco EZ Ride (200 lbs/in). On my '74 smallblock convertible, that rear spring doesn't require any more than 8" bolts. On my car, the effective bolt length for a stock "D" height, using that spring, is about 6 1/2".
Use the rubber bushings, not poly.
Put Bilstein HD shocks on all four corners, when running the stock rate springs.
The Bilstein Sport shocks are designed to work with higher rate springs.
Use the rubber bushings, not poly.
Put Bilstein HD shocks on all four corners, when running the stock rate springs.
The Bilstein Sport shocks are designed to work with higher rate springs.
Last edited by gcusmano74; Jan 15, 2013 at 10:18 PM.
Thread Starter
Instructor
Joined: Mar 2011
Posts: 127
Likes: 2
Thanks for the replies. This is not an autocross car so I'm more concerned with ride quality. The car had poly bushings all around when I bought it. The frame is torn down and off being powder coated. I ditched the poly and ordered rubber to replace everything. Sounds like the choice is between Hyperco and VB&P. I will post a full write up in the near future. Any other comments would be appreciated. Thanks again.
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
Yes Sir; I used the VB&P rear 330 # Composite & the 460 # front, Stock 1982 front sway bar, which I think is 1.25 inch, & the 9/16 G. M. stock rear. The rear spring with the 8" bolts, sitting the nuts at 1 1/2 " from the ends of the bolts to the bottom of the nuts. The front springs are bigger round, than stock & 3/4 " shorter than the stock springs, & are the same size at both ends of the spring. Bilsteins schocks all the way around, It doesn't squat when you take off, but is not harsh riding at all.. I also have Aluminiun upper A-arms, which have Rulon bushings, & all of supension has been rebuilt. Have a new Borg steering kit on my Dinning room table, will install as soon as it warms up. I had no height issues. Have a ball, on the upcoming Run. Gene
doctorgene is on it! (Wassup Doc?! 
)I tried hyperco and had to send it back..even with 8" bolts car looked like a jackrabbit
Go with VBP and you wont be sorry! 
