i've got a daily driver 383 with an edelbrok 52mm TB and have the classic whistling/sucking sound that others have mentioned on this forum. i want to drill the iac opening out a bit but can't seem to find anything that tells me what drill bit would be a good starting point.

anybody know?

thanks !

 

Just start out going slightly larger untill your happy with the results....that's what I always do... Currently, I ended up with a 1/4 inch drill bit hole....but really, every engine likes something a bit different.......Joe

 

You don't drill the IAC hole, all you have to do is sand the edges of the IAC hole to stop the whistling.