Fuel pumps on motor and nitrous

what I used was
3/8 fuel pick up in oe tank
3/8 hard line
2 regualtor one set at 7 psi for carb and the other 5 psi for nitrous
blue holey fuel pump

now I have 1/2 mancini racing fuel pick up still using OE tank
5/8 braided hose
black holley fuel pump
and still using the same set up of regulator
monted to a 3/8 npt T fitting

I hade run that set up with out problem for the last 2 years

engine is 408 with 800 cfm carb and the nitrous is a nitrous work plate
set to 125 hp