WestCoastShelby

barnett468

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The carb size depends a bit on intended purpose . . if you want to floor it from a dead stop and have less than around a 3000 rpm stall converter I would buy around a quick fuel 680 down leg vacuum secondary ss style carb . .

If you want a double pumper and want to floor it from a stop then a 625 but you will lose a bit of top end.

if you want bottom end you can also buy a carb with annular boosters.

The bog can easily be partially due to incorrect ignition timing . . I would set it so it is optimum for your particular engine.

Those gears are numerically low for that set up.
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DeepImpactPony

Looking at your dyno sheet, your max power is at 6200 RPM, with a small displacement, I would say 600-650 cfm is your best bet for good throttle response without killing your top end, you would also benefit from a better gear ratio, to allow the car to spin quicker with the better throttle response. I had a lightweight foxbody, weighing in at 3000 Lbs with driver with a 306 CID, and performer RPM intake with performer RPM heads, and a 496 liftintake with 520 lift exhaust cam, I used a 650 DP I tuned with an AOD trans with a 3500 converter, and had instantaneous throttle response, and pulled hard through 6500 rpm

kalli

Ya bit more gears. Im very happy with a 650 double pumper but I have manual transmission. 670vac sec id say would be the way to go. Am quite sure the carb you have will go very well when tuned right. And ya. Check your ignition curve not knly max timing. Max timing prob somewhere 32-34 and ijntial at around 12-14 with very fast curve leight springs. All in at 3000. Just a ballpark