Carb size

[justinsain1026]

Whats a good size carb for a smb400 stock? 600? 700?

[gdmclnh]

wouldn\'t think you would need a 700 for a stock 400 small block

[s10rodder]

650 for a stock 400. Unless it\'s mostly for the drag strip, then you could probably get away with a 750 for best peak power. For the street, nothing bigger than a 650.

[redneckgames]

do you have both? If you do try them both. see which best suits the motor.

If not then I would probably go 700 just don\'t go any higher than a 750.

[Scotty_S-15]

We could talk about this for days, and get a million answers and variations. Here\'s what I think:

* For a stock 400, 600cfm is plenty.

* But are you planning on adding big power any time soon?

* Vacuum secondary or AVS carbs are usually somewhat forgiving if oversized slightly.

* My experience: I had a 650 vac. sec. Holley on my truck for a while, ran 12.3 @ 109. Upgraded to a 750, saw no difference immediately. With tweaking, it went faster. Point is, to go that fast, need at least 400 HP, and the 650 was OK, and/or marginal.

[eigthmile]

I had a 700dp on my 383 running 7.09 in the eigth. I had a 750 built by willys carb and dyno spent about 700.00. Times stayed exactly the same. Mph went up slightly. If your gonna street drive dont go any bigger than a 650. Throttle response and torque is what\'s usefull on the street. Usually the bigger the cfm the slower the response. If you run a vacuum carb you can go bigger.

[truckinbuzzard]

no bigger than a 650. I\'m going to run a 650 on my 383. My machinist said it would be perfect for the street.