Need some advice with a transmission problem.
I have an 81 Chevy LUV 2wd diesel pickup with a 5 speed manual transmission. The transmission started making a slight knocking noise several months ago in 2nd and 5th gears. The noise progrssively worsened so I stopped driving it. This truck averages about 36 mpg and I would like to fix it.
Any recommendations where to get parts?
Are there any special tricks to removing the transmission?
I plan on tearing down and rebuiding it myself, so any advice would be very appreciated.

Thanks