So, you paid $1600 for a tranny, used it for a few hundred miles, and now you want $2000? Maybe I mis-read....
When I did an AWD swap, I sold my $2400 Shep tranny w/ Quaife diff for only $1400 and that was the best price I was offered over a 4 week span.
Either way, good luck with the sale and good luck with the swap. Too bad you didn't live any closer, or I'd offer a hand. I could probably pull one off within a weekend now.
