If you already drilled holes in the throttles you will likely need to solder them up or Jbweld them up or replace
with new. ALL ADITIONAL IDLE AIR FLOW adjustment for big cams beyond getting the pri and sec throttles idle position correct, is easily achived thru adjustment of the flow orifice in the PCV valve. Do not eliminate the PCV. It is your friend.
There are different ones with diferent flow specs. If required.
Quick fuel and AED sell carb throttle blades as replacement service parts.
Just be sure to peen lock and or Locktite the throttle blade screws so they cannot come loose.