ok, other than "don't buy them" any advice on what/how to watch for a good used stall? I see a lot of used ones come up, any way to tell the bad from good before installing?


Also, 4000 on a stock cam with 3.90s. Any issues? Tranny has 128000, am I playing with fire?

 

I would ask why the converter is for sale. If the answer is anything like "the trans went bad and the new trans came with a converter", you will absolutely want to avoid that.
If its "I simply wanted a higher/lower stall speed, that might be ok".
If its a kid "on the wrong side of the tracks", I would avoid that.
On the other hand, if the seller has a nice car, garage, tools, etc, I would be comfortable with that.

Hate to say, but with a 128,000 mile trans, you don't have that much to loose. If it were a brand new tranny, I would likely send the converter to a shop to be opened and cleaned, just to be safe.
Hey, just my opinion.