650 or 750 cfm. carb??

This is an interesting thread. I'm in the same boat as this guy. I'm haggling over carb size. I have a 360 boared .40 over with a Comp 268 extreme energy cam, edelbrock rpm intake, rpm heads, headers, and currently have a 750 dp no choke carb on it. I'm adding 125 shot of nitrous in the fall. The 750 dp drinks gas like you wouldn't believe. Ran out yesterday on the way to the gas station.

My car is primarily a street car that will see occasional track time once I complete it. I contacted Holley for the best size carb and their tech recommended a 650. I bought a 670 steet avenger to go on it but noticed that the 670 was for a mild engine. I wouldn't consider my engine "mild". They recommend a 770 for a "hot" engine (I'd say that mine is hot). What would you guys say?

It's all in the tune, I tune to the edge of lean for power and milage.

My combo was 340 .030 9.8comp, .528 solid cam, 750 dbl ,3.73 gears, ported heads, 2 1/2 exhaust etc......

I got 15 miles to the gallon, varying only 1-2mph on the street only depending on how I drove it [now it's a 410ci]

This is with 26*initial & 8* full advance @ 2200rpm=34*total timing
no vac advance
And like I said... I tune it on the edge, sometimes when it gets cold out, it'll mildly surge here and there so I go up 1 jet size till it's smooth.