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Discussion Starter · #1 ·
Hi all- so busy redoing my rearend - Im planning to upgrade the rear leafs as well- stock oem according to eaton was 125 lbs rate, the Z28 came with 175lbs (check eatons link here Product Lookup by vehicle)

A racer told me once to get 200 on the driver and 180 on the passenger- im assuming this would be a very harsh ride.. idlike something nice and in between- im thinking the 175 would be a nice balance? I do plan to take it to the strip but would also like a farely comfy ride around town without getting my teeth (and interior) knocked about -

currently the rear is as soggy as a marsh despite having new kyb gas shocks, im dropping in bilsteins at the same time-

Anyone have some SPECIFIC insight regarding the rates vs comfort vs performance?

Thanks!
 

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Helped a friend resto-mod a '74 Z28, we put 175 lb on that, with poly bushings.
Also used poly bushings, stock lower A-arms, tubular upper a-arms, and the stock springs up front.
Stock sway bars for the F41 suspension package(stock Z28) front and rear but mounted with poly bushings. IIRC we also used KYB shocks. (might have been Bilstein)

It was a really nice driver that handled well too.

I would note we took nearly 250 lbs of "energy absorbing bumper" components from behind both front and rear bumpers.....the version Chevy used on the '74-77 aluminum bumper cars was a steel C-channel inside the bumper skin as a backer bar, and a leaf spring stack laid on its side between the bumper channel and the rear body and front frame horns, along with a guide pin system to hold it all in alignment.....a ton of dead weight hanging over each end of the body.

I could scarcely believe it when I first saw it, what a Rube Goldberg contraption the bumper contrption was, couldn't believe that was a factory deal....but it was.
All we kept was the guide pins and aluminum bumper skin, and trash canned the rest.....pulled the bumpers in tighter to the body ("tucked") to our liking and then welded the sliding guide pins solid.

Car was a blast with a 400hp 355", factory 4-speed, and 3.73 gear.

Your racer has it backwards on his advice....the heavier spring goes on the passenger side if you are going to stagger rates....that is the side that tries to lift and spin easiest due to driveline torque reaction.
 

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Discussion Starter · #3 ·
gotcha - he might have said it right i was on 4 hours sleep on a long trip! thanks - 175s sound about right, ill look into that Rube creation and see how hard it is to remove!
 
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