What carb should i use for my car

[RegalBegal]

Guys, there's no such thing as those smaller Qjets you're talking about. They come in 750 and 800 castings. That's it. Anyone who tells you otherwise is wrong.

The only way to have smaller CFM than 750 or 800 is to limit the travel of the secondary air valve ( that's on top of the carb ). The factory did this on some carbs buy simply installing a tang which won't allow the air valve to open all the way. Grind,cut, or bend the tang and the air valve will open all the way.

If you want throttle response and better economy with no loss in power then the Qjet is the carb of choice. This is what they were designed for. You would be mistaken if you think any Edelbrock ( especially a cheap 'rebuilt' or 'reman' one ) is going to match a Qjet. You do realize all the Edelbrock is is the old Carter ( or is that Weber, I forget ) carb from many moons ago that was superceeded by a better carb which just so happens to be....yep, the Rochester Q-jet.

buddy im not tryin to be mean or say ur wrong but ive seen q jets as small as a 550 and i have a book with the casting numbers that say so. rochesters made q jets sized from 550 to 800. from the factory they only ran the 750 and 800s on big blocks and larger small blocks

Dude, DoubleV is correct and so are you. The Q-Jet is a VARIABLE CFM design. Like DoubleV says, it depends on the travel of the secondary air valve. There are only two CFM ratings as far as the castings are concerned, 750 and 800. Your book lists smaller CFMs and codes (not casting numbers) because those carbs are LIMITED to that max CFM rating by the secondary air valve. BTW, casting numbers are usually raised and carb codes on a Q-Jet are stamped.

Now for my two cents. On the street I would use a Q-Jet over anything else. They're not as complicated as most people think. Holley is a great race carb but their part throttle manners make them a pain on the street. As for Edelbrock (Carter) I'm not too crazy about the design. Of course, opinions are like a$$holes, everybody's got one.

 

[MyMonte1]

(Engine Displacement (c.i.d.) x Max RPM)divided by 3,456 = Ideal Carb CFM

 

[DoubleV]

(Engine Displacement (c.i.d.) x Max RPM)divided by 3,456 = Ideal Carb CFM

This is simply not true.