I'm looking at a used 500cfm carb for $50 that supposedly still works, but needs a Ford A/T kickdown arm. If I buy it, I'll swap that pump over and let you know what I find. I just drive so far daily that I can't afford to kill my mileage.
Just omit the kickdown and do it manually. Just remember to not jerk the shifter down while nailing the go pedal at the same time. Seems I recall that'll kill a C-4 without a kickdown. I don't have one on the 3x2's never has hurt the C-4 behind it either.
A 500 2-barrel will give you more upper RPM power, but will be sluggish off-the-line on a stock motor. The smart thing is a smallish 4-barrel.
No, it will not. Try it before you knock it. Will it be a little less responsive than a smaller carb ? Yea, but it will be anything but sluggish. First 500 I bought got put on a 69 Ford Club Wagon's stock 302 (7000 lbs) it was anything but sluggish, compared to the stock carb it replaced. It was years before I swapped on a stock 4 bbl intake and 600 Holley, it was then I regretted not sticking with the 500. There was no difference I could recall with the 600.
I have a 500cfm 2bl Holley on my 66 mustang 302 with tri-y long tube headers, best carb I've ever owned.. When I bought it I was on a budget and couldn't afford a intake, I will never change it now because it runs better than my 600 4bl Holley on my maverick... Don't be afraid to use the Holley 2bl there great...
Compared to a small 4-barrel, I stand by my statement. It is a known fact that smaller venturis produce crispier low-RPM throttle response. The secondaries of the 4-barrel would then make up the difference for mid and high RPM breathing. On a stock 289/302, there's no way the 500 2V is gonna out-perform a 500 to 600cfm Edelbrock or Holley, or even a Q-jet that's been tuned for smallblock applications. I know the circle-track guys love the 500 2V carb, but those aren't stock street motors either.
I can't see how even a 500 CFM 2bbl would give anywhere nearly it's optimum potential feeding through a stock manifold... Now if it were ported significantly... Anyway I've never had much luck with a large 2bbl, always were flat just off idle at light throttle, a small 4bbl always had better throttle response... I'm liking the 670 Avenger that's on my 428 enough that I'd like to try the 570 version on the 306 going in the Comet, but with two different 600 Holleys around here(one is new) probably ain't gonna happen...
You said it would be sluggish. It is anything but sluggish on a stock 302. The 500 is exactly half of a 750 cfm 4 bbl. I've run a VS 750 on a stock 302 and it was not sluggish. I'm speaking from actual experience with the 500, you are not.
CFM is measured differently between a 2 bbl than it is with a 4 bbl The Holley 500 2 bbl flows 353.55 cfm if you use the 4 bbl formula. 4 bbl is measured at 3" of vacuum...2 bbl is measured at 1.5" of vacuum
Exactly! And a 750cfm carb is too big and will have sluggish low-end throttle response on a stock or even mildly modified smallblock Ford. I say "sluggish" compared to a 500 or 600cfm 4-barrel. I think you just enjoy disagreeing with me.
Now you're nitpicking to save face Try it before you knock it. I've actually run both a 500 2bbl and a 750 4 bbl on a 302. Neither were sluggish. Now, seeing that you're in Colorado, ANY carb you run will be sluggish. Been there - done that too.
isn't this only relevant if you are using a converter to put a 4bbl on a 2bbl intake or vice versa? I'm pretty sure that is the case. That is why a 500CFM Holley is exactly half of a 750. On a 2bbl intake its a 500 CFM, on a 4bbl intake it's half a 750.
