Junk yard shopping for a ECM

Ok so I am new to this game and can see I will be needing to learn at lot of new stuff in tuning, So I am thinking Ii will goto u pull it and get a ECM as my test mule, My first thoughts is to get one from truck just like mine but is that the best idea? how do you know if its any good? smell it to see if its burnt.

My truck is a 95 K2500, 350 TBI, 4L60, A/C, cruise control, power windows. Note some people call this a heavy half or 3/4 light, it has the 14 bolt rear end with I think the 9.5 floating.

Most likely you have a 16197427 pcm but there are other possibilities. Look for the service number on the pcm behind the glovebox.