Can anyone educate me on exactly what the sequence of introduction and production of the old Merc Hi-Perf drives. I wasn't around then, and am having trouble making sense of it from the service manuals and parts lists.

BAM shows the old III clubfoot going back as far as 1968-1972. I assume that the later III SSM shared the transom, gimbal and upper from the III, but supposedly was not introduced until 1982. Meanwhile, the TR/TRS/II drive shows production from 1973-1993.

So, what happened with the III during those 10 years, and was 1982 indeed the first III Speedmasters? I'm pretty clear on the SSM's after that. Main reason I am asking is that I have a '79 Cigarette that had SSM III's (now V's), but there's no evidence of it ever being rigged with anything else.

Thanks!