Can someone tell me what these are and what they do? I noticed my later model (85) block doesn't have them. Also can I run an FB Racing Beat header on this SA block which looks like will cover up the holes?

 

Secondary air injection ports; part of the emissions system when using Thermal Reactor exhaust. Must be a pre-81 engine?

It's OK if the header blocks them, just be sure to use blocking plates for the ACV and Heat Exchanger ports on the intake manifold, too.

 

The header blocks the holes up. I'm running the same 12A engine with an RB header in my car now.

 

Should I use the SA header gasket or the FB one?

 

Won't really matter much since the header plate blocks off the other side of the hole. The FB one is probably cheaper or easier to find. Just make sure it's for a 12A.

 

Thanks for the help.

 

I don't have any of the factory stuff. The car I bought came with the 12A and the RB street header and RB gasket.


Well the car came with a blown up 13B but thats beside the point.