So I'm went with a ZZ4 cam upgrade on the maro, but I really didn't do much research as far as head springs and things in that nature but a guy here in this site recommended these springs but I'm reading on the website that these are LT4 springs, will these fit my stock L98 heads?


Here's the link
http://paceperformance.com/index.asp...D&ProdID=24732

 

I think those are 1.32" in diameter and I dont think the stock head spring pocket can take much over 1.26" or so which is about stock diameter I think. I'm not 100% sure but for stock replacement, the comp 981's work well. For any decent hyd roller, you will want a double spring like patriot golds, AFR 8017's, similar. Or beehives from comp.

 

Isky's 235-D spring is stock diameter and will easily handle the ZZ4 cam. Might have to get the top of the valve guides machined down some, or use +.050 offset spring retainers for the extra lift. I had a set of stock 083 heads set up with these springs and my machinist just machined the guides for positive seals and used standard height retainers, and there was plenty of clearance for the ZZ4 lift specs. Personally, I'd avoid any GM valve spring. They're weak garbage compared to most aftermarket springs.