Carb help Needed, 750 CFM too much?

Hey all, I NEED YOUR OPNION!

I have a 302 Ford with 289 Heads and a pretty wild Cam. Im wanting to change to a smaller intake and carb.

Currently, I have a Tunnel Ram with two 450's on it. It runs well, but I am running a direct linkage, instead of a progressive linkage, so it will stumble a little if I hit the gas too quick. I have them leaned out all the way. Im also wanting to get rid of the 70s look.

Im going to get a RPM Air Gap manifold, and either a Edelbrock 600 with elect choke or a Edelbrock 750 with elect choke. Im leaning towards the 750 and getting a carb kit if it is too much.

What are your opnions, will the 600 be enough? Will it be not enough? Will the 750 be too much? How easy is it to jet the 750 down a little if Im not happy with it?

Thanks for the help!

 

what do you use it for mostly? street duty? strip?
what is your gear ratio? auto trans.? converter?

 

i think 750 too much for a street small block.

 

On a typical street engine 302 500 CFM is adequate, I vote for the 600. It should take care of the bog.

 

Street Duty, strip on occasion.

3:73 Rear with 31X18.5 (yes, its prostreeted, get over it, I still need help). I plan to un-prostreet it and go with a normal tire on the rear someday.

 

A 750 vacuum secondaries carb will work fine on your intended combo, and will provide excellent power throughout the rpm range at the expense of fuel economy, of course.

A 600 vacuum secondaries carb will still provide adeqate power, but will give you crisper throttle response off-idle and through the lower revs. Naturally, fuel milegae will be a little better as well.

Or, you could split the difference and run a Holley 670 Street Avenger carb, which would be a very strong performer on your SBF in a light car with 3.73 gears!

 

pretty much exactly that.

I forgot about the street avengers...they are very nice, user friendly.
oh, yeah...I don't get all angry when I see narrowed rears ...

 

How high do you rev it? If you're really turning that thing 600 or 650 may be a little small for strip use.

You could always split the difference, holley makes a 700 double pumper that's one of my faves for street/strip small blocks. Good luck!

 

if you can drive it with a tunnel ram, you should be fine with a 750 on a normal intake.

600 is about right, 750 is a bit large, but the Edelbrock carb does have that air valve in the secondaries to help you get going without a lean bog

 

i agree with all of the above, i have found on the street less cfm is better, youll be happier

 

670 Street Avenger is garbage in my opinion, there is one on my Dad's Factory 5 cobra with a 347 stroker edelbrock heads, air gap intake, all roller engine, the powerband is like a light switch 4200 and up you better have it aimed where you want it to go. I would go with the 600, I plan on putting that 600 that was on his 67 442 on the cobra when I go home next.

 

Unless you have some real good heads better go with the 600cfm you'll be much happier. N.N.

 

I had a pretty radical 302 and the 750 was too much carb. A 600 made her run very well!

 

i agree a 600 should be plenty i have a 500 afb on my stock 302 and it runs much better then the 650 i removed if you want a 750 use a vacuum secondary holley with a strong spring did your tunnel ram have the mechaical secondary carbs i call them sucker carbs cause they're really only good for cars with 5000 rpm converters that come of the line full throttle you could keep your tunnel ram and run 2 400 cfm afb,s or 2 390 -450 vac sec holeys with progressive linkage john