Originally Posted by eatonde
I'm currently working with a holley 600 cfm street/strip carb. A guy on here yesterday told me i should go to a 750cfm for my engine set up. i was wundering if i whould have to get a hole new carb or if i could just put bigger jets in the one i have. I've never really worked on carbs, other than pullin the bowls, floats and needles for cleanin purposes can anybody tell me if this is possible and mabey how to do it. the part # on my carb is 80457. Thanks
Without knowing what engine is and how it's set up it's impossible to say anything about carb size other than 600 or 750 relates to air flow capability which is related to venturi and throttle bore size. This has nothing to do with jet sizes which control main well fuel flow which is one contributing element that establishes the fuel to air mixture ratio. One could assume that a bigger air flow carb would also require larger main fuel jets, but life and carbs aren't that easy. The rest of the engine such as displacement, compression ratio, operating temperature, spark lead, type of cylinder head and piston crown shape, cam timing, type of intake manifold, the carb itself, type of exhaust, even the air cleaner assembly are some of the many elements that will affect jetting.