For the 305, you really dont want to go over 600cfm, which would be the Edelbrock 1405 (manual choke), or 1406 (electric choke). And those are for the square bore performer carbs. I bought an Edelbrock 1405 600cfm, and it works great. I almost got a 750cfm for my 305, until I was told by many people that its too small of a motor to handle it.
Also, what are the numbers on your quadra jets carbs, i can look them up and see how many cfm's they are.
- Shane
