Im finally puttin my zex kit in on my 97 ls with 100k miles on it motor seems good don't blow smoke and have had no problems with the zex kit im installin aem fuel rail rc 270cc injectors b&m command flow regulator aem fuel filter do u think i need a fuel pump cause i really don't want to have any problems and if so is walbro the way to go im also nervous about puttin an aftermarket fuel pump in cause sometimes aftermaket parts are jus not built the same as oem and if somthin goes wrong with the fuel pump while jucin good bye motor
PS
on a 97 ls with dc sports 4-2-1 header straight pipe world sport exhaust and aem cold air would run a 1/4 in with a 75 dry shot