the 5 speed, the nvg3550, was used until 2003. then the nsg370(i think), took over as the 6 speed. from what ive read and heard the 5 speed is a stronger tranny, but the 6 speed does have a lower 1st gear... and in all reality im sure the 6 speed will do just fine. so really, if you like it then wheel it. aint that the point;)