I was checking my pushrod length and my length varies from front to back of engine .025." I'm using stock block deck and the pistons all checked right at about .006" to .010" out of the hole. The heads are brand new PRC stage 2.5 5.3l heads. I can't understand why the lengths vary this much. What is the recommended lifter preload for ls7 lifters?

 

Seems its widely accepted at .060-.100

 

I believe hes talking about the pr length to achieve the same preload on each valve. I measured mine many times as I am running short travel lifters. I saw about that same amount of variation across my motor and I covered it with 4 lengths of custom pushrods.

I have discussed this a few times with Tony Mamo and this is right at the range he haS seen after careful measurement. The majority of the tolerance seems to follow the rocker arm, valve height can also vary by several thousandths as well.