How to tell a 82-87 700R4 from a 88-92?

[lukecp]

I'm looking to buy a 700R4 to get rebuilt and stick in my '72. I found one at a salvage yard that needs rebuilt for $45. How will i tell if it is a 82-87 one or a 88-92? I don't want to get a older model, they are alot weaker i hear. I found a tranny decoder on the internet, and it showed which number in the vehicle VIN stamped on the tranny to look at for the year, but it only shows the last number in the year, like 3=1983. That wouldn't be a problem, but i don't want to get stuck with a '82 700R4 thinking it is a '92 model. Are they any physical differences on the outside of the case, or any other numbers i can look at? Also, the tranny guy said that i can use a lockup converter, and he can wire a switch and put it on my dash so i can have it lock or unlock whenever i want. Does that seem like a good idea? 2 other questions, can i modify my shift linkage so i can hold the tranny in 1st gear, and would a RV-style shift kit give me a nice firm shift, and bark the tires in the 1-2 shift when i mash the throttle? I don't want it to shift to hard all the time, but i would like that nice little "chirp" when the RPM's are high so i can show off a little .