…...between that used on early gearsets and modern later versions --- it won't work. I spent what seemed like at least a day trying to fit a modern shift drum and forks to an early transmission. No matter how quick I moved my hands --- it did not work. So, I started looking at what I had in a box, and lookie here, this might work! The forks without "Ducati" and the gear numbers on them must go on the early drum with the big empty band going all the way around it (on the left). Gears were very narrow then. Later gears got progressively wider and there was no longer room for that empty band. The forks are also spindly on the early sets, and all three are the same. I guess I had forgotten the last engine, in the replica factory Pantah racer. MikeV

Since You are so into mixing gearboxes : does a Sixspeed SS350 Junior fits into a SS600 of about the same year?
I just like the sound of a twin on overrun so much I'm happy to trade in some tenths of a second per lap, just to hear it

ciao
ducadini

Hoestly, l don’t know with certainty, but if you got all the components it is probably a drop-in. I will eventually try that too. I do know that Ducati once advertised the small six speed gearset as a performance item for the later small case engines. MikeV