[Rust-O-Matic]

I put 5" 1/2 ton coils in the rear of my '66 C20, and 3" 1/2 ton coils in the front. With the original bump stops removed there's still a reasonable amount of suspension travel. Anything shorter than 3" springs on the front will not stay seated in the control arm pockets if you jack it up under the frame, and let the arms hang down.

My first attempt was to cut two coils off the original front springs (4-ish inches) and it was way too low. The springs didn't stay seated and there was about an inch between the tire tread and the inner fenders. Hence, the half ton springs.