i just got my car back from getting an aod to t-5 swap. i have a 1989 w/ mass air (CA car) and the donor t-5 was from a 1990 GT......i believe the speedo cluster is different, but my mechanic also said my speedometer will be off....whats the easiest way to fix this? thanks.... by the way my car still ahs the dumb 85mph speedo....not the 140mph, thanks!