What kind of posi unit is this?

[72seeten]

You all are starting to scare me w/ all these horror stories, maybe I shouldn't use it.

I have yet another question, I have heard different things about this. The truck has a 700r4, and the lockup converter is not hooked up. From the numbers on the side of the case, I've identified it as an 85 model. Will it eventually burn up w/ out the lockup? The truck has 3.07 or something "highway", cause it is barely above idle at 50 or so in OD. I'd rather just go w/out hooking it up if I don't need to. Some say you have to have it, others say it will work just fine.