[A26B]

Originally Posted by SAM/CH ZR-1

I measured by a 1990 head the with stock cams and lifters the lifter pre-load and got 0.097". With stage 1 cams the pre-load drop to 0.051"and with stage 2 to 0.025". To make the lifters work properly a minimum pre-load of 0.040-0.070" is required otherwise you can loose valve opening duration and get a noisy valve train. The situation become worse with the shorter 93-95 MY valves.

Your experience with the different cams sounds right with my thinking too. If you're going to get real nit-picky, the exhaust valve stem height should be set about 0.010" less lifter compression to account for thermal growth.

Total lifter travel is pretty darn close to 0.124". Setting stem height to pre-load or compress the lifter, right in the middle of the travel range @ 0.062" will work well for both intake & exhaust valves.