[dana44]

Which thermoquad are you talking about? The Rochester or Carter style? I like the Mopar spreadbore style thermoquad, not the Rochester so much. The 750 is actually a pretty good match for your 400, secondary opening with the proper spring pressure (spring adjustments), are usually pretty decent, but I am kind of partial to the Holley carbs anyway.

 

[dana44]

Thanks for the updated information. It's kind of like the six pack I have for my 440 Charger. 1350cfm is more than the engine could ever suck, it is more the image of owning it, whereas 750cfm is still a little more than what the engine can ever pull in, especially on the street, so for the money, 50cfm is almost impossible to experience or know it is there.