It is an awesome tranny. The NP-435 also has bragging rights, with the lowest first gear ratio of all the domestic trannies...that being 6.69:1. I have one in my '80 and it has 450,000 km on it, without ever being opened up. I also have a spare one, but sorry, not for sale as I'm selling truck with all my "spare" stuff together.
The Hauler - '05 F-350 4x4 CC Dually 6.0 Powerstroke
The Project - '90 Ford Bronco 4x4
The wife's - '11 Ford Escape
For every minute you are away from work...you can add two minutes to your life!