thanks for the reply, so i installed the the pushrod checker until there was no slack, rotated the engine a couple times by hand after marked the top of the valve tip, trying to get the pattern in the middle then measured it. ordered the push rods, although i did not account the preload, so how would i account for this, so if i get a measurement of 6.945 accounting for preload i should go 0.25-0.40 longer so in the 6.975 range? these are magnum stock roller lifters and stock rockers 1.6