17056256 is the number on the carb. So this would be a 4bbl carb from 1976 on my "appears to be original I think 1971 455"
Regardless, I'm trying to see how many cfms this carb is and can't find a definate answer. Does anyone know? I've read 750, I've read 800 and I've read 850. Because these carbs were designed to adjust, but I'd think there's be a maximum cfm rating. Admittedly, I don't know too much about carbs. I've messed with plenty of bike carbs but never a car carb. These quadrajets don't sound like bad carbs but it seems that you either like em or you hate em.
Back to the original question, can anyone tell me what the cfm rating is on this particular carb?

 

As far as I know, a 1976 QuadraJet would be a 750 cfm carb. The 800 cfm carbs arrived on the scene in 1977, along with the 403 engines.

 

Why did 403s need more CFM than a big block?

 

The 850 CFM carbs have a bump inside the primaries, but I can't quite describe it - easy enough to google a picture of it, though.

It doesn't matter anyway, because if you have a 455 with the usual 85%-ish efficiency level, and rev it (optimistically) to 5,500 RPM, you only need 600 CFM.

- Eric

 

2:40 and 2:58

 

Thanks, Chris!