well i have a 92 civic which has a chipped p75 and a stock b18c and i am changing the fuel pump and the one i bought is a quantum 255 lph and im assuming the pump in the car is a stock eg civic pump so my question is should i change the fuel pressure regulator on the stock motor to an aftermarket one or does anyone think its not needed an i should just leave the stock regulator on and drop the pump in ?

 

You'll be fine to just drop the pump in, no other modifications or tune required.

Won't quite be optimal, but won't damage or significantly impact anything.