Originally Posted by LS1Silverado05

Lets assume for a minute a perfect 1.800 installed height (but I cant be 100%)

Springs claim a .625 lift....
Cam had max lift of .603....
7.425 Pushrods
LS7 Lifters (+.060 over LS1)
Stock Head and Gasket....

Could the LS7 Lifters and 7.425 even on a 1.800 installed height cause a bind or at least been way too close for comfort? I understand that they are hydraulic lifters and that its end user that should measure but damn .060 is alot to not know about...I wish GM advertised that!

Originally Posted by PREDATOR-Z

You were running too much preload which could have bottomed/ or close to, the lifter. Kinda like running non hydraulic. That with cold spring and added bad harmonic resonnance could have caused the spring to shatter at a higher rpm. (this is just speculation).

Originally Posted by LS1Silverado05

**Update**

LS7 lifters are official GM LS1/LS6 replacement lifters, wht GM fails to mention is that LS7 lifters have aproximately .060 higher cup and require shorter pushrods to re-establish preload in the correct range.