Thread: stock 302 carb?

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ok fellas
you guys have never let me down so far so here goes.
i have a stock rebuilt 1981 ford 302 engine.
i got it with a holley 4412 carb.
it is my understanding that the carb is primarily used by circle track racers
and as such doesnt really belong on this engine.
my question will probably seem out of place on a hotrod forum but
what carb will give me the very best gas milage in a 2300lbs car with a 3.00 rear end and c6 tranny?

Billy, I would try to locate a 600 cfm 4 barrel with electric choke and vacuum secondaries. I actually am using right now a Road Demon 525 cfm w\electric choke and vacuum secondaries and am pleasantly surprised with it so far considering the stories I heard. A stock 302 ford (depending on year) won't need more than 600 cfm.

Of course, imho, ymmv, my 02, yada yada yada... 8-)

Originally Posted by 34_40

Billy, I would try to locate a 600 cfm 4 barrel with electric choke and vacuum secondaries. I actually am using right now a Road Demon 525 cfm w\electric choke and vacuum secondaries and am pleasantly surprised with it so far considering the stories I heard. A stock 302 ford (depending on year) won't need more than 600 cfm.

Of course, imho, ymmv, my 02, yada yada yada... 8-)

i thought the 500 was too big?

i havent opened it up yet.
but i did take some vacuum movies.
one is of the engine in drive

and the other is me punching the throttle


from what i have read i should put the automatic tranny in drive and the divide my vac reading by 1/2 and that would be the correct power valve to use.
so i guess that would be a 6.5 Hg

i just don't want it to die at stoplights and bog way down when accelerating anymore

Originally Posted by billy zz

i thought the 500 was too big?

Nah, a lot of folks think the limit is a 650 cfm, I agree!. A square bore holley 600 should be perfect. IMHO!

Originally Posted by billy zz

one is of the engine in drive

In this picture it should be reading 14 inches or better depending on rpm! I hope you mixxed up the pics and used the same one twice.

Originally Posted by 34_40

In this picture it should be reading 14 inches or better depending on rpm! I hope you mixxed up the pics and used the same one twice.

i dont know why this one website wont let me show a movie
idling in drive 14Hg

Originally Posted by billy zz

here is a movie
idling in drive

Nope, jpg is a picture! At zero vacuum!

the other film is useless as a still photo

idling in drive
vaccuum002.mp4 video by billhedges - Photobucket

punching throttle
i dont know if you can hear it crapping out or not.

vaccuum003.mp4 video by billhedges - Photobucket

That's better! I'd consider 14 inches a bit low. Have you tried adjusting the needle valves by reading the vacuum gauge? Slowly turn in then out to achieve the highest gauge reading and then try driving it like that. Looks like you have a mechanical choke too that isn't connected. It may help on those cold mornings.

Originally Posted by 34_40

That's better! I'd consider 14 inches a bit low. Have you tried adjusting the needle valves by reading the vacuum gauge? Slowly turn in then out to achieve the highest gauge reading and then try driving it like that. Looks like you have a mechanical choke too that isn't connected. It may help on those cold mornings.

i havent tried adjusting those yet
and i also havent hooked up that choke.
the only carb i have ever fooled with is the 50 year old carter on my antique jeep
so this is another learning experience for me,

i just walked in from adjusting as per your instruction
right at 16 inches