Back in the early 60's, I had a couple of friends who drove Austin-Healey 3000's that had a 4-speed and overdrive. I remember one of them telling me that since the overdrive was electically activated, you could rig a switch and wind up with what amounted to an 8-speed trans. That is, 4 forward gears, and overdrive in each gear. I don't know how true that was, and I never rode in one that was set up that way, but it sure sounded interesting.
