Ok when i bought my second GN the guy had a second ecm.He said it was a racing one that he had made and with it in the car was like night and day.There are no numbers on just some wright that says 87 grand national and on the cover that covers the chip i say's metric.There wer some guys there that offerd me 1500 bucks for the ecm but I decided to keep it .The chip looks stock and when i put it in the car it had a up and down idel to it.I never drov it with it in because i changed injecters and it was running real rich.Any clue about this ecm I know those two guys wanted it bad....