Edelbrock 600 electric choke and it's way better that my old 2bbl setup

 

I think too many people read magazines and listen to other people when it comes to carbs. By looking at your sig I would guess it is too big for you ap. But 750 is not always to big for a 302 by any means. It doesn't need to be a race motor, or rev to 8k. Intake manifolding even has a role in it. I have done my own personally testing back to back and have seen it on my car that was 9.2-1 CR. The 650 couldn't get the wheels off the ground, but the 750 would 60ft better, and MPH higher. I'm just saying I wouldn't rule it out just because the size of the motor. -Dustin

 

Size is important on street cars where throttle response and mileage is a concern. And smaller carbs atomise fuel better, more completely atomised/vaporized fuel = better combustion = better power, provided everything is setup right.

 

Correct. But I think that little bit of atomization would pale in comparison to actually jetting as far down as you can and making the appropriate metering block changes for WOT.

 

I am running a 750 Holley vacuum secondary on a 302. I had to install a larger squirt nozzle after going with the 4.5 power valve(because of the cam)to lose the hesitation. It responds crisp and pulls way up into the rpm range.I am not saying I would put one on a stock 302, but well built it will use every bit of it.

 

You're talking about a strip machine running at WOT, we're talking about a carburetor on a street car. It's all about throttle response and fuel atomization on the street. Running a carb that large you'dprobably have to upjet to get the proper amount of fuel in the engine. When you increase the venturi size, you decrease the vacuum signal which decreases the amount of fuel being pulled into the engine. You can tune out some of the driveability issues, but it's horribly inefficient at lower rpm's.

 

That's my point. I'm not talking about a strip machine only at WOT. I'm talking about a motor that alot of people run. Something that requires a 3k stall, maybe a little higher if more drag oriented. Atomization as a reason to run a smaller carb, I'm saying is splitting hairs. And fuel mileage is not enough to make me put on a smaller carb when I can jet it down, and tinker with the PVCR's and probably end up with MPG within 1 of a smaller carb. Street or strip throttle response is only 10% of the game. Split second after the pedal is down, the vacuum under the baseplate is what goes on for the next 10-15 seconds as opposed to the split secong in the beginning. But again I say, manifold has to be taken account also. I would run a 600 on a single plain, or a 750 on a dual, rather than vise versa.

 

Throttle response is NOT 10% of the game on the street. You want a street car to be driveable, not to have to spend hours trying to tune out hesitation caused by overcarbing, which you'll likely never completely get rid of.

Again, I think you're talking about a much more aggressive motor than most people are running. A 3k stall converter isridiculously high for a street car. A street engine is going to spend most of its time under 4k rpm, probably under 3k for most people. This is where overcarbing really hurts because you're not pulling enough vacuum to properly pull fuel through the jets. There's no point dumping a 750CFM carb on a moderately built,street-driven 289 to get that extra 5hp on the top end at WOT when you have to sacrifice low-end torque and throttle response for it. You're never going to notice the gain outside of a dyno, but you'll definitely notice the driveability issues. And what small gains you do get will be offset by the loss of low-end power due to poor fuel atomization.

 

Stock 2 barrel. Edelbrock 500 cfm when some cash comes my way

 

well i'm running 2 500 Edelbrocks on a f-28 intake 302 small roller and Edelbrock heads in a 65 fb with tremec 5 speed and 3.70 gears getting 15 to 16 mpg and it is a blast to drive and throttle response is great
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