First of all, the AIR pump. Can I use an AIR pump off of an LT1 car? Is there a way to wire a relay into the current switch so that it turns on to route air as soon as the signal is given to divert air to the cat? I'm going to eliminate the AIR tubes on the headers but keep the tube to the cat. I want to route my belt a bit differently, though haven't decided exactly how yet.

Also, for the throttle bodies...are they 48mm or 52mm? I have an LT1 intake sitting here and a throttle body gasket that came in the stock intake gasket set and it is a 52mm gasket (as is the intake's bore). Are the bores just 52mm, but the actual throttle body itself is just 48mm?

 

IIRC the air diverter cycles, it does not give a continuous flow to the cat. The ECM also compensates for this as well. Why that is, I don't think anyone every postulated a theory. IIRC it was posted in DIY buy Timmay!.

 

I'm pretty sure it does divert 100% when in closed loop. If that's the case, I should be able to wire up a relay to energize when it receives the signal that would normally divert the air. In this case the ECM would say "divert AIR" and the electric AIR pump would then turn on and put air to the cat..