eddy 650 or 750

750, either edelbrock or Holley. Better to go bigger, it will only use what fuel it needs (after it's tuned) even though it can provide more. I have run a dp that came with my car until I swapped engines, then went with eddy. Both provide about the same results.

Check with snap-on to see if they still have a bushing kit for the throttle shaft, if you want to keep the carb.