what might be your problem is that the Performer intake # 2101 has Q-jet carb  spread bore mounting flange, the Holley Avenger  has a square mounting flange, to run the avenger on the #2101 manifold you have to get Edelbrock #2696 adopter which lifts the carb about 1/2" or use # 9265 or 9266 heat insulator  gasket, the difference between the 65 and 66 is one has a divider and the other is open, either one will work, I used the heat gasket on my Edel 2101  because I didn't like the the adapter set up which uses two gaskets and a alumn spacer and longer studs, the heat insulator uses a 3/8" gasket and longer studs, so before doing surgery on you carb, make sure your carb is mounted correctly, your mech should have picked  up the difference in the mounting.

what might be your problem is that the Performer intake # 2101 has Q-jet carb  spread bore mounting flange, the Holley Avenger  has a square mounting flange, to run the avenger on the #2101 manifold you have to get Edelbrock #2696 adopter which lifts the carb about 1/2" or use # 9265 or 9266 heat insulator  gasket, I used the heat gasket on my Edel 2101  because I didn't like the the adapter set up which uses two gaskets and a alumn spacer, the heat insulator uses a 3/8" gasket and longer studs.