Motorcycle Repair: 1983 650 xs Yamaha 3rd gear, xs650, basket case

Question
Mike,

We just purchased a 83 XS650 - it had a tranmission noise. We've torn it down - 3rd gear needs to be replace.

We have a 81 XT550 basket case -

Of course in the manuels they look the same and part numbers dont match on all the websites.

can we interchange 3rd gear from the XT550 to the XS650?

Hoping it might work!
Thanks Kelly  

Answer
I usually only answer questions on harleys, but I may be able to help. If the pat numbers are different then they are probably not interchangable. The might have a different number of teeth or a different teeth pitch.
Good luck and happy riding
Mike