Carb cfm?

[89CamaroRS]

Hey guys, i'm trying to find a 650 or 750 cfm demon carb and there's a kid on another board who has one but doesn't know what cfm it is. he had it on a 302 so i'm skeptical as to whether or not it'll be big enough. i suggested he get the serial number off it and call barry grant. now he says he cant find the serial number. anyone have any experience with demon carbs and know where they might hide the SN?

[johnjzjz]

its the size of the throttle blades that determine the size - with the venturi - 650 / 750 does it matter for what you need the smaller one will get better fuel mileage -- we put 750s on 454 cars all the time to make them run better and get more mileage -- jz

[WildBillyT]

its the size of the throttle blades that determine the size - with the venturi - 650 / 750 does it matter for what you need the smaller one will get better fuel mileage -- we put 750s on 454 cars all the time to make them run better and get more mileage -- jz

Somewhere I have a PDF from Holley that lists carb sizes with venturi sizes. I will see if I can dig it up and maybe you can cross reference it. I had to do that when I bought a Holley with the choke horn (and thus list number) milled off.

[johnjzjz]

Somewhere I have a PDF from Holley that lists carb sizes with venturi sizes. I will see if I can dig it up and maybe you can cross reference it. I had to do that when I bought a Holley with the choke horn (and thus list number) milled off.

HEY bill performance carbs and i am sure you know this dont conform to stock sheets - we had put a 850 bottom on a 650 carb and fluffed the bottom to match the larger hole - custon carbs like he has could be a 670 715 and alike -- jz

[68camaroguy]

i have a 650 speed demon that just needs some gaskets

[89CamaroRS]

i have a 650 speed demon that just needs some gaskets

the only reason i didn't jump on that in your classified's thread is i've never rebuilt one before. Is it overly complicated or expensive?

[johnjzjz]

Its really easy - the hard part it the old gaskets are a PITA to get off but we have found spray aircraft paint stripper in the blue can in wally mart works real well spray on 1/2 hour later scrape ( brass tooth brush dollar store ) than spray again 1/2 hour and use mineral spirits to wash assembly in - than at the end use a spray can of carb cleaner --NOTE -- lots of smells and you are using paint stripper so gloves are a must and spray in a place thats ok with that - a holley book available in barnes and nobel is a good thing take your time read it and follow its that simple -- you get in a jam you can always PM -- i can help but their are plenty of guys on here that will also help no question about setting it up cant be answered as well as tuning on this site -- jz