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Engine Specs: Junkyard 6.0 (LQ4), Summit 8709R1 Cam (0.625/0.605 Lift), 317 Heads milled 0.020", LS7 Lifters, dual 0.660" valve springs. (Main, Connecting Rod, and Cam bearings are all brand new)
Background: I recently put together my 6.0 (LQ4) and have noticed extremely loud valvetrain noise. After some investigation I've identified that my pushrods are too short and the engine has excessive lash. I've identified this using the turn-method of checking pre-load to which I appear to have 1/4 - 1/2 turn to go from zero-lash to 22-lbft torqued on the rockers. And being that my pushrods show signs of degradation [see picture below, pushrods from this build on the right with ~20 minutes of run time, compared to regular junkyard pushrod left].
Question (HELP): I'm trying to understand why my pushrods would be too short... With the heads milled 0.020" and LS7 lifters (0.050" taller cup) I would think if anything I would need shorter pushrods.... Does it sound right that I would need longer pushrods on this setup based solely on the likely smaller base circle of the cam (it is relatively "high lift")? Additionally, I'm trying to figure out if I should go with 7.425" or 7.450" pushrods... any recommendations?
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Pushrods Too Short - Help Me Understand (Please) 
