I put a 78 output shaft in a 76 motor.
I had to machine the "stop" for the big
outboard bearing over @ 14mm inboard.
Also had to use the gears from the 76
trans. (different teeth count)
It moved the drive sprocket outbound
about 1/2" over stock. Yes I could have just
bought a sprocket from cycleX but this didn't
cost me anything!

Check the parts manuals and fiche to see how much of
the trannies are interchangeable and go from there.
Also, inspect all the gears carefully. It's an awful lot of
work to have to do twice! Or, three times!

Snake Oil? Isn't that what Suzuki's run on?