Which aftermarket valve covers will work with the factory A/C bracket? I was really looking for to installing the GM Performance covers buy they are too tall for the factory bracket.

 

Pretty much, none of them. If you want to run A/C with tall valve covers, adapt the R4 compressor and brackets from a 307 Olds. The shorter R4 compressor fits entirely in front of the passenger side valve cover.

 

Well thats disappointing to hear...

 

buy the pro6ten compressor. It's 22 lbs lighter than stock. You don't need to use the rear bracket that goes over the valve cover...but it's around $400....

JoeLincoln71442014.jpg

 

Or you can modify or fab your own brackets.

 

Presumably, the reason one needs tall valve covers is to clear adjustable roller rockers, which in turn were needed to run an aftermarket cam. If one is going to this trouble for additional HP, why retain the 16 ton A6 compressor and associated cast iron brackets? More weight seems to defeat the purpose of adding HP.

 

The valve covers pictured,are just like the stock ones,but taller.There are roller rockers & rocker stud girdles under those.I believe I removed the baffles,but don't remember.The girdles act as a baffle,basicly not giving oil a straight shot to the breather hole.I had mocked-up the factory AC compressor with those,and it will work.The rear alternator H-shaped bracket will work as well,but I think you need to clearance it some,or not use it at all.The main bracket is stiff enough to run alone.

 

Does the AC / alternator bracket advice go for a ['71] 350 as well? I'd like a cleaner look under the hood.

 

As an aerospace engineer who's designed and flown a lot of structures under severe vibration environments, I'm going to disagree with this. First, GM does not typically install parts that are not required. Second, the issue is fatigue over time. You may get away with leaving this bracket off on a drag car or cruiser that sees very little annual mileage, but I certainly wouldn't recommend it for a car that sees a lot of street driving. Not only does the bracket itself get fatigue loaded and crack, but you run the risk of damaging the attach points on the head as well. You certainly don't need the complete H bracket, but a strut from the upper alternator bolt to the intake will both clear the valve cover and go a long way towards stabilizing the bracket.

 

GM deleted the alt brace to intake in '72, guess they decided it was overkill..

 

I used the notched V/C's from inline tube with dbl gaskets. had to modify the breather baffles as they were hitting the poly locks. (Howard roller rockers). the a/c bracket needed grinding on the underside & you must notch the bracket where it sits on the intake. with the ebrock intake the bolt hole does not line up. Alternator bracket needed some gentle persuasion but not as much as the a/c

 

Hope this helps