hello i just bout a 90 300zx n.a and im converting to tt ..i got offerend 10 used nismo old style 555 for 250 all reading 11.5 to 12 ..should i grab them i know about the fail rate and the mod to stop the 12v constant but want bigger injectors and 600 to a 1000 for new style is out my range they were bout in 04 and says there good he just upgraded