I need a new transmission in my 85 k20. It currently has an auto, Since I Prefer a manual it seems like a perfect time to swap. Looking for a Transmission I went on Car-Part.com. It asked me if I needed a MT, (4 speed), side cover or 4x4 top cover. I didn't know what the difference was so I called a local junk yard to see if they had a transmission. They asked the same question. When I asked what the difference was the response was a bunch of errrrs, n umms. So being that I am swapping transmissions what's the difference and is one better to use or is it just thing GM did to make things more complicated when finding parts? One other question. I am sure many threads have covered this so any good threads have answers to best places to get the misc. parts I'll need(aka pedal, clutch etc)?