750 vs. 800cfm Rochester Quadrajets-how to tell them apart

There exists a ton of misinformation regarding the actual airflow capacity of the Rochester Quadrajet. Not many people know how many variations there are or how to tell them apart. Here is a simple video explaining how to identify each size based on casting design. I will cover the "cfm-limited" carbs in a separate video.

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Let's look at a factory high-performance Quadrajet
These late 70's Pontiac Quadrajets are probably the best of the post-1975 "modified" Qjets. They were originally installed on 77-79 Pontiac 400 engines. Fairly rare.





Decoding a Rochester Quadrajet part 1: The name
Rochester Quadrajets tend to mystify people because of the various model names assigned to them by GM. Add to that a redesign in the '70s and the confusion only grows. In this video we'll learn the different model names and also how to differentiate between early and later-model Qjets. Enjoy!





Why Quadrajet's are awesome part 1





#3 Quadrajet main body--Kickin' Holley Butt
Google the #s on your QJ. If GM put it on an engine of a different size than what you are going to use it on, then you need to recalibrate it. Watch and learn.




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