I'm 5' 10" and the belt fits fine.

As for converting to 74 setup, aftermarket rear panels can be modified to look like 74 panels. But a GOOD rectangular plastic bezel that goes on the panel where the belt comes thru is pure unobtainium. I have 2 sets and both are crappy and chalky. Just BAD plastic from back in the day.

Heres some pics of a NICE, oem setup from another Moparts member....