Mustang II 302 carb

[Fulcrum]

Hi, I haven't been around for a few months but reviewing the forum I came across your inquiry about a carb for your Mustang II 302. If you haven't done anything yet let me offer a wordy suggestion. I currently have a '79 302, like your car it was a 2-barrel.
My previous experience with the 302 goes back to a '69 Mustang that also came stock with the 2-barrel/single exhaust setup that my brother had in the late seventies. When we replaced the 2-barrel with a Holley 600 vac secondaries the 302 really bogged down. Yet the same carb when placed in a '68 Couger I owned that came stock with a 289 4-barrel, woke the 289 right up. The difference I believe were the heads. The '70 302 had smaller valves.
Your '78 302 and incidently my '79 302 are the same engines. The stock intake valves are 1.60 and the exhaust are 1.4 something. You place a 650cfm on that and your engine WILL bog and you will become upset and possibly discouraged. If your not going to replace your heads, then go with something in the 450cfm range. It will still wake your car up. At that power level a stock ford 4-barrel intake will work but an aftermarket one will be even better. Stick to the dual-plane style for better streetability. Also, if you would like to install the carb and forget it and have good performace, check out the Edlebrock line. The Holleys are fantastic but like some women, they can be high maintainance.