650 dp vs 750 dp in a 408

It really doesn’t matter what you have in the car !! If it runs better with the 650 !! Well it runs better !! Had a friend years ago decided he needed a 850 dp. So he bought one ! The car went from 6:80 1/8 to 7:05 1/8 ! He put his 750 vac sec back on ran 6:80’s again . 62 Chevy 2 383 small block ! Sometimes just leaving the carb alone is worth a lot !! And sometimes trying different things makes your car go faster !!


It’s 408 INCHES. That’s why I asked the OP what I did.

There is no excuse for the 650 being the better carb. I’d like to see the time slips as well.

Either there was something wrong with the 750, or the MPH went up but the ET went down (more HP less bite) or something.

A decent, modern 750 today will flow 930-950 CFM easily. That’s better than the used up 4779 series carbs. And yet, they make more power and drive better than the 4779 carbs.