Performer RPM to RPM Air Gap Swap-350 chev
 

Just wondering if anybody has any advise on what sort of tuning changes can I expect when I swap this Performer RPM intake with a Perf. RPM Air-Gap ? I will be using a 1/2" carb spacer and the carburetor is a Holley 750 DBL pump, no choke or air-horn. I guess I just need to know if I should expect to change jets or Power valve or anything at all ? Thanks for your help.

Tuning changes? none. it's a direct swap.

I like the air gaps, not necessarily for the "cooler" open intake runners... but you can feed vacuum lines, coolant temp wires, fuel lines.... etc thru the open center and it looks cleaner

You will need a manual choke to drive the thing below 50* temp.
Cold weather will be a pain, I promise you. You will probably need a carb air intake heater.

You will see little if any power gain between the manifolds.

You won't notice a darn thing. At best you might gain a couple HP. It also depends on the other parts of the engine; cam, compression, heads? Depending on how its set up, you could be going the wrong direction.

Air gaps don't make more power from a cooler intake charge because they reach the same temperature as non-air-gap, it just takes longer. During that longer warm up time you will experience a more "cold-blooded" operation.