I have L98 heads from a 91 z28 motor with stock valve springs.
My question is how much lift can i subject them to. Within a safe range.
Thanks,
Dane

 

Any lift at all is too much. THey are garbage. They don't even have enough pressure at the seat, at zero lift.

 

Well since he feels so strongly against using them could any one suggest a good valve spring to use on my heads that can support over .510 lift.
Thanks,
Dane

 

comp, lunati, and crane make good springs. i prefer lunati stuff and rb likes comp.

 

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springs are springs there is no roller spring or flat cam spring. you need a spring with enough seat and open preasure to match your cam. call comp or lunati and ask about a stock type replacement spring. as for roller rockers i use either the roller tip from comp or the full roller from comp, only roller rockers i'll put on an engine.