Most pro-magnum lifters I have used call for .002 to .004 lifter preload with the engine warm. If you dont have instructions with your lifters you should call comp-cams and check. If they call for .002 to .004 preload and you have them at .025 to .030 your valves will not close all the way.

5038109-440lifters.jpg (65 downloads)
Last edited by DRAGSLICK; 02/19/09 08:40 PM.