Duane...regarding the Holley carburetor...Holley's ad in their website is very misleading. They show a legal replacement carburetor for Stock and Super Stock, however, they show a carburetor with four corner idle.
http://www.holley.com/types/Competition.asp
Then look at the specific carburetor, with the choke plate, however, you cannot see if it has the idle screws in the rear. Interestting is the carburetor does not have the choke linkage, but if you look at the tower, there is a drilled hole to lock the choke plate in the open position.
Open up this page:
http://www.holley.com/0-4609-1.asp
This is the specific carburetor...NHRA approved for Stock and Super Stock...