NEVER put a 750 on a 318........

Jarlaxle said
Mopar put 800cfm carbs on 150hp smogger 318s. GM put 750cfm carbs on 4.3 and 4.1 litre V6 engines, in heavy cars with tall gears!

I drove a truck with a 750cfm carb on a 370ci engine that never topped 3500RPM.

RustyRatRod said
Exactly. What people simple cannot get through their heads is, carburetors like the Thermoquad and Quadrajet are unusual carburetors, even though millions of each were used. They are a mechanical/vacuum hybrid. I can close the secondaries on either one COMPLETELTY OFF and run only on the primaries. What size is the carburetor then? 280 CFM? Maybe? That's why they are so forgiving. You can run one on a slant 6 and tune it to run well, pull it right off, put it in a 440 and re-tune it for the 440. Some people just cannot get their heads around that.

And the other thing people forget (or are unaware) is the fact that as soon as you put a 750 cfm carb or whatever on a 318, it becomes the cfm carb the engine will pull because it will only flow what the engine will pull.