Mine is similar to yours in a lot of ways. 508 street car, small roller, shift around 6400, Indy dual plane, 950 carb with 0.110" N&S, stock converter. 4150 lbs and runs in the high 11s at 120 mph with a 1.9 sec 60 ft.

I have 3/8" line and a Mallory 140 pump regulated to 6 psi. It runs about 4 psi down the track and through the traps. If you're lifting the tires off the ground, consider 1/2".