Refurbishing Suspensions
Short answer: A member’s front+rear refresh on a 1968 400 (new springs, bushings, front ball joints): the result was about an inch more ride height front and rear, tight steering, and no more bottoming out. Notes and one gotcha below.
- Front: standard MOOG bushings/ball joints and Classic Industries coil springs; a machine shop did the control-arm work. Lining the lower control arms up with the frame on reassembly is the hard part.
- Rear: Classic Industries leaf springs and mounting kit. The new spring’s extra bottom mounting plate made the stack too thick, so he removed it; he reused the original (shorter) U-bolts and the more-secure cinch-type shackle nuts rather than the kit’s plain longer ones. All bolts must be torqued with the car on the ground — a lift or pit helps.
- Stick with plain rubber (GM-style) bushings over urethane/solid mounts for a streetable ride.
The gotcha: a loud, very-low-frequency road noise at 30–40 mph turned out to be the new shackles rubbing the body — their bolt holes were ~1/4″ farther apart, so the bottom edge contacted the panel below the rear bumper.
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Content last modified: June 13, 2026 at 10:06 am
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