how to tell the size of a carburator

[4eyepride]

hello i have a holley carburator that the last owner told me is a 830cfm hp 4150. i took to this guy to rebuilt yesterday and he tells me is a 750 and i say is a 830 how can i tell what size it is???

 

[EHA Racing]

You have to send it to a carb place like ProSystems and have it flowed. It's almost impossible to tell because most carbs share the same main body and base plates. The same base plate will worok on a 750 and 850.

 

[sbeachstang]

Dougs right for true CFM, if it has a choke, there will be a list number on it (exp. 4777-7) for the advertised cfm from holley. do a search there are alot of websites with holley list numbers with original jet sizes.

 

[stanginthe11s]

tell me the #s on the carb and post a pic if you can.

 

[EHA Racing]

Just as an example my Pro-systems carb is an 850 main body and base plate but flows 930cfm. Who knows if 4eyed's carb is an off the shelf carb or if it has been modified. The oly way to know for sure is to have it flowed. If all you are looking for is what the carb was based on than the serial numbers will work.