I have 173,000 miles and counting on my original 5 speed NV 4500 trans. It is starting to make some bearing noises when in fifth gear. So I am hoping for the best but preparing for the worst. I plan to start collecting parts before it goes. Once fifth gear goes, I figure I will rebuild the entire trans rather than just repair the gear. I want to know the best place to get a rebuild kit and also what is the best way to solve the issue of losing fifth gear. Will a fully splined shaft for fifth gear solve that issue once and for all? Also, what clutch is the best to get while still being as easy to use as the stock one? I still have the original clutch.

As always, thanks in advance and Happy New Year!