75-80hp shot total between two plates got me a .160 improvement in the 1/8th mile alone, and the short time fell off 2/100ths because I wadded up the tire. Car is 3300lb with me, 383 SBC with 11 lbs, TH400 off the brake.
A blower significantly heats up the intake charge, nitrous cools it back down and acts as an intercooler. A little bottle goes a long way with a blower.
Here are the two passes back to back:
Pass #1
83 degrees / 35% humidity / 2268 corrected altitiude
.572 r/t
1.412 60'
4.168 330'
6.484 1/8
105.53 mph
Pass #2 with 75hp shot of nitrous
85 degrees / 35% humidity / 2402 corrected altitude
.618 r/t
1.436 60'
4.117 330'
6.324 1/8
111.35 mph