I like the pushrod length checker method, seems to be the easiest without further questions or concerns. .030 to .080 is what was recommended to me by WCCH (check the lifter pre-load sticky up top), but I have heard of guys running over .100 without any problems. If the pre-load is too much, valvetrain damage may occur, such as bent pushrods, broken rockers (probably not with the GENII rockers), or damaged lifters (seems to be the weak link from what I've learned on this forum).

I'd get a pushrod length checker for less than $20 and get it right the first time. Worst case scenario, you have to buy some shorter pushrods and sell what you've got

 

This is what I've always understood to be the best. When I change cam/lifters on mine I'm going to aim for .040 to .070. I personally wouldn't run close to, or over .100 of preload.

 

Lifter preload theories seem to be a big ordeal and everyone has different ideas and different reason to do things the way they see as the "right way"...I personally like more preload than less preload. When I did the cam and Procharger in my truck, I threw a set of 7.400's in on the stock lifters and had close to, but under .100" of preload. With the new motor, I swapped to the LS7 lifter, which has a cup that is .050" higher than the stock lifter cups. I swapped to Comp Hi-Tek 7.350" pushrods to keep the preload exactly where I had it before.

There are lots of theories that higher lifter preload yields different gains within the valve event and make your cam/lifter/pushrod/rocker/valve assembly react differently (more aggressively) when compared to lower preloads.

Bottom line, it all comes down to what you agree with and what you feel safe running in your own vehicle!

 

You guys should see how much an LS7 motor runs. I think you would all die then.

R

 

How much, you big tease?

 

Hey, Hey!!! Only the ladies can ask that one. LOL

Usually I see a good 1-2 turns on all the LS7 stuff.

R