I think the R-154 gearbox was only offered in the supra. In the trucks the most common transmission is the R-150. They also used the R-151, but only for two years, only in the pickups and only behind the turbo motor. Fortunately I beleive most of the internals in R series transmissions are the same. Did your car come with the R-154 from the factory? Behind what motor? I thought that the supra had a six speed gearbox.