How much clearance do stock style centerbolt valve covers have? Will roller rockers and .550 lift clear? I may or may not run a stud girdle...havn't decided.

If not, did anyone ever start making taller covers?

Thanks

 

I got them for mine 89 (and I am using 1.6 rockers)

http://www.gmpartsdirect.com/perform...CATID=777.html

 

Thanks man..but that link goes to perimiter bolt covers...

 

they do make a conversion kit from CB to original style now..

 

Polylocks on roller tip rockers wont clear the stock covers by a minimal amount. That help?

 

Hmm.. so you can use old-school covers on CB heads? Who makes this and how much? I never even thought twice about roller rockers not fitting under stock covers.. until now!

 

it will probably need a pretty thick gasket.
http://www.gmpartsdirect.com/perform...CATID=777.html

 

Jester..

I just purchased a set for my Vortec's....T D Performance pn 6986

They were around $110 at Summit

They measure 3.625 from the surface of the gasket to the inside top of the cover

Hope this helps

 

I'm running .520 lift, 1.5 RR with poly locks. Everything clears. By how much, I don't know.

 

I assume you mean with stock valve covers and not the TD ones described above? If so..that would do me nicely.

 

I used some adapters to perimeter valve covers on mine .525 lift, didn't like them due to leaks. I spent about 2 hours grinding out the centerbolts and I don't see why they wouldn't clear .550 lift. If you want the adapters they are for sale, though I don't recommend them.

 

Lift isn't the problem with valve cover clearance. The height of the poly-lock, and the width & length of the rocker, is where you get into trouble. Most rockers and poly-lock combos are not too tall to fit under most stock valve covers. Some rockers are very long on the push rod end, such that they will hit the intake side of the valve cover. Most, but not all, roller rocker trunnions are wide enough that the stock oil separator won't fit between them. No way a stud girdle will fit under any stock valve covers I've ever seen, due to the height. It wouldn't be too hard to make some spacers though, you'd need probably 3/8 - 1/2" extra.

I was running stock L98 valve covers on my 400, with .544"/.554" of lift, Comp 1102 stainless RRs, 186 "double-hump" heads, .150" longer than "nominal" push rods (which raised the rockers and poly-locks by that same amount). I had to sodomize the oil separators to get them to fit. I also had to use the thick ROL gasket on top of a FelPro VS12869R to get them to clear, and I had to grind the oil drippers back to little nubs.