[Mike C]

I run 35's on my Jimmy with a 4" lift. It has Rancho springs in the front and National springs in the rear. I started out with blocks in the back (2 1/2") combined with an add-a-leaf. But the 35's combined with 4.10 gears and the 4 speed bent the perches on both sides.

I R&R'd the perches and added the springs. That was 25 years ago and that's still the combo on it today.

I know Special K and I have debated it, but my experience with blocks has not been good and I would encourage springs all the way around.

BUT, with that said, I have an '86 K30 dually. 454, 4 speed that I bought a Superlift 3 1/2" kit for and in order to keep payload and overloads in place, will run blocks. YMMV....