im running 2 holley blue fuel pumps, the thing is with these cheap regulators and fuel pressure gauges they tend to fluctuate alot, especially when there hot. so their hard to read at different times. i usally set them when the cars cold. the carbs pump is set at 7-8psi. the nitrous pump is set at about 6-7psi (while its being sprayed) mean when i flow the fuel side of the nitrous the lowest the pressure drops to is 6-7psi. so if i jus turn on that pump and leave it on the pressure will build up pretty high, but thats not my concern cause its only on when i turn it on to actually spray it. my concern is how low it drops while im spraying it. the first time i spray it i left it with the original ac delco plugs and burnt the strap off #1 cylinder it was to lean. now i got NGK #6 plugs in it and 10* of timing on the 150 shot. ino its alot but ima start backing out the timing slowly, or jus go up in shot. for now i try to flow the fuel side of the nitrous before i run so ino its rite where i need it until i do better regulators and gauges.