Quote:
	
	
		| 
					Originally Posted by DAVID GAGNARD  Using Holley's formula for determining carb cfm requirements of a given engine  (cubic inches X max rpms diveded by 3456) assuming a 6000 rpm redline, your engine would need 574.66 cfms of air, also, assuming 100% VE....Add in antoher 50 cfm so you don't max out the carb and you need 624.66 cfms of air, so a 650 double pumper would be perfect....you would have good idle vacum and good low end torque as well as enough carb to see it through the rpm range......a lot of times when it comes to carbs,bigger is not better.....
 
 David
 | 
	
 
I used to use that formula, with pretty much the same result.
Then I found out the motor made more power with a 780.