Is one better then the other? Was thinking I could combine the parts and make 1 working carb. But which one? Thanks
Hey There.The 72`& 74` Qjets are 800 cfm,good choice.From what I have learned,the 75`-`76`s are not that good "performance" wise.I had a choice between a `74 and a `75 to build.I used the`74 carb.So far so good!! :TU: Later,Tony.
When Edelbrock wanted to sell a performance version of the Q-Jet, they based it off of the '75--up "Mod Quad" castings. That became the #1910 Q-Jet RPM carb. ANYTIME you mix 'n' match OEM carb castings, you had better be a friggin' expert with carbs 'cause there's more different versions than you can shake a stick at. If you're good with details, and verify that every passage needed is where it should be, fine. First guess: Pick an one of those carbs--any of those you mention have potential--and rebuild it. Play with jets, metering rods, float levels, power valve springs, and secondary hangers as needed to get you where you need to be. By the way, Edelbrock made Q-Jet tuning kits, one for the 74-older, and one for the '75-newer castings. Might want to see if you can still get one.
Carbs that begin with 70, and carbs that begin with 170 have different primary rods. The 170 rods are .080 shorter and with a different taper. I'm sure the castings are different also. The 72 is a good carb. The 7042240 is an 800 CFM for the 455
