I was wondering if anybody's done it yet and what springs they used. I am trying to get away with not taking the heads off and doing valve springs and seals at the same time. Sonmeone mentioned that the valve guides may need to be machined down to accept the cams .510 lift. Any ideas?

 

I'm going to bump this up for you as I was about to ask the same question. I might be putting on an LT1 intake and while I was at it I was thinking of putting in the ZZ4 cam. I too do not want to mess with taking off the heads.

I have done alot of research on it and there are some guys who claim that they put in the cam straight up without taking off the heads and have had no problems. One guy even said that he has had it in his car for 90,000 miles without any modifications to the heads.

 

Anybody know FOR SURE>>>?????? I got the parts on the shelf waiting for an answer! :lala: PLEEEEEASE!!!! :hail:

 

With stock heads, you're on the ragged edge of rocker stud pull-out. Won't happen to everybody, but could very well happen to you.

Best bet would be to pull the heads, install screw-in studs (or pin the pull-outs you've got now), cut the guides for positive stem seals, put it all back together with new springs & retainers.