I backed my 250 with a NP A833/MY6/89mm 4 speed overdrive from 81-86 Chevy truck. Easier install than the T5, it bolted right up. I'm really pleased with it (8000 miles now since 12/02), cruising 80mph no problem and getting 20MPG on the highway (16mpg in-town). Only trick is finding one.

http://www.chuckthetruck.homestead.com/page12.html