With the convertor and lack of gear, I'd go smaller. Street Avenger 570, or the Thunder AVS 650, or the 650 vaccum secondary Holley. No need for larger.
I agree also, No need for a larger carb with the lack of gear & stall, A 750dp will work good if you plan on installing a better converter & better gears like 3.91s & a 32-3400 stall.
I ran a 650dp with a 2800 stall & 3.73 gears on my mild 360 (small cam), it ran great. If i had went with more cam, steeper gears & a better stall, i would have ungraded to a 750dp.