i remember hearing you can identify a the larger cfm quadrajets by a bump inside each of the primary or secondry bores does any one know which it is a pictire would help thanks

 

it's in my doug roe book, but i'll be damned, I can't find the book...

IIRC - you measure the primary throttle bores - 1 7/32" is 750cfm, and 1 11/32" is the 800CFM unit.
Supervisor showed me and easy way to check for the 650CFM units, stick an 11/32" drill bit down the bore between the venturi and the wall, if it fits, it's a 750CFM unit... (I might be off on that size).

Also, a 800cfm q-jet would usually only be found on a big block in the JY. All other motors would have had the 750CFM

 

And if it's computer controlled they're all the smaller 750 units. I've never run across a computer controlled 800 CFM unit.