Mustang II 302 carb

[wellsyd]

I have just aquired a 1978 Mustang II project with a 302 engine. I am in the process of rebuilding the engine and want to replace the seized motorcraft carb with a Holley one. Could anyone out there give me a clue as to what model Holley will best suit the car? It doesn't need to be race tuned , just functional. Any help most appreciated.

[ralph s]

i use a 650. trick kit is a must have in my opinion. im thinking to try larger carbs later w/ vac secondaries just to experiment.

[wellsyd]

Thanks for the info but to show my complete ignorance of things Holley related , What's a trick kit?

[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.

[Phillyfanfrombirth]

Holley 600 with vacuum secondaries...

Buy a spring kit and experiment with the different springs, it was my experience that took out "bogging"... and really perked up the performance.

I agree with Fulcrum on the dual plane manifold... Edelbrock Performer and Performer RPMs are both good choices.

[wellsyd]

Thanks very much for the info, So far i've bought a Holley 650 double pumper and a ford 4-barrel intake. Can the stock heads be machined to accept large valves or will need to get the different heads. I'm not sure how different springs will take out bogging as surely it's a case of getting a larger charge of mixture through the engine more efficiently,(big carb, big valves) however if it works i'm willing to try it. thanks again all info most welcome

[Fulcrum]

Sorry it took me so long to get back, being an OTR driver, I don't get home much, and when I do it's brief. What have you done? To answer your question about having the heads machined for larger valves... yeah, you can do that. BUT for the same cost range you can pick up the Roush 180 or 200 heads. I choose the 180 because the head chambers where smaller giving a higher compresion ratio.