My truck was having starting problems so i started troubleshooting it a few weeks ago and narrowed down to a weak fuel pump. it would read 50psi with key on then drop to 0psi in about 5 seconds, 43-44psi at idle. replacing the pump fixed the starting problem but im still running at 44-45 psi at idle. i decided to try replacing the fuel pressure regulator and see what happens and ran into another problem i think. my truck is a 02 silverado 1500 LS 5.3L vin T, the regulator thats suppose to go on there does not fit, the on that is on there is a vin Z (flex fuel). there is a big diff between the pressures vin T 55-62psi and vin Z 48-54 psi. my question is, are the injectors the same between flex fuel and gas? any input on this will be greatly appreciated, im running in circles on this one