Ok, first you insulted my man, Yount, which pissed me off, but then you seemed to be cool again. But then you insulted me by saying your post was the best response, now you've really pissed me off. I think anyone that puts a 5.0 in a chevy, 240Z, or Volvo gets props in my eyes, though I'd prefer to have one in a 240Z. I dont agree with the Edelbrock because I've had them on 2 different cars and each time the thing ran horrible and I hate them so much. Not only are they a horrible performance carb, parts are limited for them, they run like crap, and you cant use them for blowthrough. I dont think you have any right getting pissy to anyone NEWB so I recommend cooling your jets. There is no question, the car needs a 600 to 650 cfm Holley or Demon. Whether he wants vac or mech. secondaries is more of a personal preference. The actual correct size for a 306 with 6000 rpm max, dual plane intake, and 85% VE is 542-677 cfms. The larger being more performance oriented, but anything in that range will work fine for his car. For great performance, perfect cfm for the specified range given above, and great streetability, and price, I recommend the Road Demon 625. It comes with fuel line, electric choke, vacuum secondaries, its cfm rating is perfect, and its cheap at $340.