LT1 Manifold question, bear with me please.
 

If you take the throttle body off and look into the manifold right past throttle blade openings there are two round holes right inside towards center line on the bottom. What are they for? PCV?

Probably IAC. I can only think of one hole to look at when the throttle body is off...

This isnt my manifold, but I circles the area and you can see a portion of the holes within the manifold. Its not IAC, as those holes are little and within the actual runners. The main feed for the IAC is up front.
http://i280.photobucket.com/albums/k...lt1ported2.jpg

Blow air in the PCV vacuum port below the throttle body bores, and see if the air comes out of the two holes in the intake.

I will try it this evening. Thanks,

Yep, its part of the pcv system. So, we need to make sure our PCV system is in proper working order to ensure no vacuum leaks can be attributed to it.

The PCV system is an intentional vacuum leak. But if you have the system hooked up the way the factory designed it, it is pulling in air from the throttle body that has been filtered, and accounted for by the MAF sensor (unless you have a 93.... but you don't have a signature, so we have no idea if that's the case).

I am a 93.

You really need to add a "signature" after being here for 4 years. :rolleyes:

I will right now. Sorry about that.