i'm looking to put a stage two cams in my dohc zc, and i know i need to uograde my timing, valvetrain, cam gears.. but now i'm having tourble find the ecu, i dont know what ecu to run i have seen the pm7,pm6, and om4 ran. which one do i need to run and what system. it is a OBD 0 motor. i was also told to run the OBD1 pr4 or the OBD 1 pr75.