ome, here is a photo of my setup.
It is a Tecumseh 5 speed, used in lawn tractors and walk behind mowers. It has 5 speeds, ranging from about 100 fpm to 400 fpm. Can't remember for sure, it been too many years since I did the calculations/measurements. The second set of pulleys adds 5 more speeds. The additional speeds are all faster than the low range, so there is no belt swapping as you work your way up through the soeeds.
Things you need to know about the transmission.
The gear selection is sequential. All the way up, you are in reverse. Down one is neutral. Then low, second, etc.
The sprocket has a splined bore and there is only one size available. It takes #40 chain, so it is plenty rugged. The input speed is design limited to 2200 rpm. The speed range is good enough that I never go to the high speed pulleys when cutting metals. High might be a little slow for some when cutting aluminum. Neutral is fantastic when changing blades!
Over the years I had collected several of the transmission, they were free and I thought they might be useful. The stuff that I had would not make a transmission with the desired speeds, so I purchased one that was four speed. It was not exactly what I wanted (I was getting pretty particular) but was able to assmble a transmission to my liking. The gearboxes were often used in applications that did not require all speeds, so they use only the speeds needed. One was only two speeds! They used compatible internal components, even the ones with H pattern gearshift.
Bill