I found an old holley double pumper carb in all the parts ive collected over time, and was wondering is there a way of determining the size of the carb, meaning cfms without a chokehorn, i guess the choke horn has been milled off so i dont know what size it really is.. on the other hand assuming its a 600 cfm can you swap the body for a bigger cfm body. its currently going a 455 so i guess i need a 800+ carb for mine. can you tell by the size of the butterflies.. thanks
Maybe this will help ...butterflies on my newer Holley 850 double pumper are stamped 180....my 750 Barry Grant Double pumpers - Speed Demon are stamped 169. Here is a link to some baseplates and their cfm ranges...scroll about 1/2 way down the page......... . http://www.carburetion.com/holley.asp
both the front and back butterflies are stamped with the numbers 172...i will try posting pics tomorrow..thanks
This website is pretty good reference site..I noticed that the 3310 baseplate does have the 172 172 butterflies, also that it is a vac secondary, but mines is not a vac secondary, i will try getting a pic tomorrow, as soon as i pick it up.. i also noticed the numbers 4778 numbers on the metering blocks... anyways ill post pics tomorrow.
If you post the main body number I have a Holley book that has the metering block #s and base plate#, jets, power valve(s) & shooters etc it had when made. If there is no body id # the book also has the size of veturi's and throttle bores, fuel bowl part #'s etc to figure out what you have. Ray
The "4778" is the list number which can be found also on the metering blocks. So a "4778" is a 700 CFM double pumper carb.
sorry guys i had the carb at the machine shop (cleaning) after a while of waiting, it was not cleaned...:eek2: anyways here are the pics..what pics do you need to determine what size this is..even though i bought a quickfuel 830 s/s i still want something to work on and build. thanks