ok i have 977 springs with compr lifters but i keep hearing all this about preload. what are they refering to as preload. i cant just torque them down to 22 ft pounds like stock rockers. i was told by a sponser that i can but 40 thousanths shims on and torque them down to 22ft pounds. i dont nkow what to do can someone please explain to me what preload is thanks

 

That's the number of turns you get on the rocker bolts from the start of resistance to the point that they bottom out. For stock lifters, 1/4 to 1 turn is about right; I think the Comp R's run with less but maybe someone will chime in that knows for sure.

 

I was also told this...hope it works..

 

Lifter Preload is the distance the inner piston in the hydraulic lifter is from the top of it's travel when the lifter is on the base circle of the cam and the rest of the valve train is in place and secured.