how to tell a 750Qjet from a 800 Qjet
 

please tell me
My carb # is 17056502 do you know if this is a 750cfm ?

Re: how to tell a 750Qjet from a 800 Qjet
 

Look through the primary venturi and there is a ring/step on the outside of the bore. The 800 has a narrow ring and the 750 is wider. If you have both sitting side by side it is easier to tell. After you look at enough of them you will be able tell easily. This is the easiest way to tell quickly but you could measure the venturi as it is called out in the NHRA specs as 1.093 for a 750 cfm.

Rob Turkal

Re: how to tell a 750Qjet from a 800 Qjet
 

Lonnie, On the 1.21 venturi carbs, the top screw that's inside the choke horn, will just about fall through between the venturi cluster (booster ring) and the outer wall. On the 1.09 it won't be close.
After studying that area, you'll be able to tell be the shape and curvature of the venturi wall.

Re: how to tell a 750Qjet from a 800 Qjet
 

My carb # is 17056502

Re: how to tell a 750Qjet from a 800 Qjet
 

If you hold primaries open.......Is there not a Flat area on. 800 where it is
perfectly round on 750 outside walls?

BTW. I have a supply of Edelbrock Replacement Q jets all # and sizes.