There is an interesting truck on YouTube, a '56 GMC 660 with a 4-71 Detroit and a 10-Speed Road Ranger. Truck looks like an 18 or 20 Ft Flatbed with Budd Wheels, what looks like 10-20 Tires and has Air Brakes. I have to say it's one of the coolest trucks I've ever seen. The truck also has a Factory Tach, but interestingly no Speedometer. Especially interesting to me is the RR Trans. It is an R-960, one I've never heard of and has a Shift Pattern that I've also never seen:
R------1/6-----3/8
--------N--------
5/10--2/7-----4/9
It's a long video, over 1 hr, but pretty interesting if anyone would like to check it out:
https://www.youtube.com/watch?v=-5rJoFAxbC8