I have a question, and I couldn't really find what I wanted to know with the magic search button

I'm going to get a set of full roller rockers, Comp or Crane 1.5 ratio.

What I'm wondering is if rockers that use polylocks like these will fit under valve covers roughly the same height as stock perimeter bolt valve covers? I have a set of aluminum Holley valve covers (same as the old M/T valve covers) which are about the same height as stock steel valve covers, maybe a little bit taller, and I'd like to know if a set of full rollers and their polylocks will fit under these covers? Or will I need to change to the 'tall' style?

The only info I could find was about center bolt valve covers. Mine are perimeter bolt.

 

This may not help much but I had M/T valve covers on the BB in my Monte Carlo.These are slightly taller and squared off where the stock covers curve in.There wasn't a clearance problem with the ploy locks/full roller rocker arms.Now if you go with a girdle too you'll have a problem.If the Holley covers are taller than the stock height covers you shouldn't have any problem.I don't know whether the stock center bolt covers will be any problems.

 

I won't be using a stud girdle. These covers seem to be just slightly taller than stock GM stuff, and more 'squared off' like you said.

 

I have 1.6:1 Comp Cam roller rockers under my factory covers with no problem.

 

Those would be centerbolt, correct? Are those any taller than perimeter bolt valve covers?

 

Dont know if this will help, but I have the center bolt stock covers from a 95 LT1 (pretty short covers) and have Comp Cams Pro Mag RR's under them without issue. The Pro Mags are Chromemoly and do not have as much material as aluminum rockers. I dont know if I could fit the aluminum rockers. The Pro Mags are really nice rockers and better than aluminum IMO anyway.

 

91' What did you do about the baffles? any trimming on them?
Couldn't get mine to fit on the CB covers with them in there.
Might have been more like I couldn't get them on with them still sticking down so far. don't totally remember why last year.
I'm running stock height perimiters now because the tall ones hit my A/C lines. no problem with them.
Edit: Mine are Harland's BTW.

 

You will have to run narrow body self aligning rockers and they will fit with no problem.
If you buy a wide body rocker you will have to flatten the supports inside the valvecover to get the cover to clear between the rocker. Takes a few tries to get them to clear just right and can be a pita. But just takes a pair of pliers to get the job done.

I usually use the crane gold's self aligning and they fit w/o any need to mess with the cover. Also I think the harland sharps will fit as well as the proforms. Comp promags need clearanced.

Height wise they fit no problem as long as your not runnin a stud girdle as mentioned.