Carburetor CFM Rating?

[Larry Gibson]

I have a 7029244 carb which is for a 69 - 350 automatic car. What is the CFM rating for this carb? Is it 730? I should probably know this but I don't. I know the big blocks were 730 cfm but am not sure about the small blocks.

Thanks,

Larry

[David G]

750cfm

[Larry Gibson]

750cfm

David,

Thanks for posting. I had a friend tell me the same thing the other day. Now I know.

Larry

[Carl Rychlik]

The cfm rating for the big blocks was 730 cfm,but for the small blocks the rating would have to be lower probably around 650 cfm. The 315 h.p. 350 used the same cfm rating as the non-stage 455.

[David G]

That's interesting. I've read the 750cfm info posted around by numerous guys that I'd have thought would know for sure. Where do you find the 730 info?

[NailHdking]

the really old q jets like the '66 carb I run is rated at 730CFM, but most of the later ones were 650,750, and 800 cfm... for what its worth Jerry

[woody45]

Is there a reference chart that shows the CFM ratings for id numbers. Two numbers I'm intrested in at the monent are #7043244/7044240.
I know they are both 350 carbs but I wanted to find out before I bought either one. I could tell if they 800 cfm carbs if I could look at them but I cant. I haven't been able to locate a chart lists the carb number and it's cfm rating, Is there such a thing?
Thanks, Woody

[71stage1conv]

The way I remember the number breakdown is:
7043244 = 70 rochester, 4 buick, 3 is 1973, 244 is 350 engine (750cfm)
7044240 = 70 rochester, 4 buick, 4 is 1974, 240 is 455 engine (800cfm)

[bumble]

I had John Osborne help me with my carb over the summer through emails. I have a 455 and thought the Q-jets only came in 750 and 800 cfm so I told him I had an 800 cfm version because I knew it was a 1973 carb. When I gave him the number he said I had a 350 Q-jet and it was a 600 or 650 cfm carb. Apparently there is a little tab on the secondary air valve linkage that controls how far the valve opens. The tab can be shortened to allow the full 750 or 800 cfm by allowing the valve to open fully. Who knew.

Mark