I have a 1980 FLT with a 5 speed transmission that got stuck between gears & am looking for another one. Harley Davidson says it's an obsolete part so no luck there, any suggestions?  

Why not repair it?

The shifter cams are readily available as are complete gear sets.

If you what to get a little crazy, I think you can probably fit one of the "six speed in a 5 speed box" sets availble by Baker and Revtec.

In most cases you can replace the gearset without even removing the tranny from the bike.

Good luck