I'm guessing that you've seen this site already, but just in case you haven't:
http://www.f-117a.com/ATA.html
Characteristics of ATA "A" and ATA "B" (February 1978)
| ATA "A" | ATA "B" |
Mission radius | 400 n mile | 1000 n mile |
Payload | 5000 lb | 7500 lb |
TOGW | 43,000 lb | 90,000 lb |
Length | 64 ft | 76 ft |
Wingspan | 43 ft | 47 ft |
Crew | 1 | 2 |
Number of engines | 2 | 2 |
Engine type | GE F404[br](nonafterburning variant) | GE F101[br]("partially" afterburning) |
Cost | x | 1.5x |
That table is apparently based on data in the AIAA book
Have Blue and the F-117A: Evolution of the "Stealth Fighter" by David C. Aronstein, Albert C. Piccirillo, which I don't have. Excerpts of that book are in Google Books, but most of the ATA Version A vs Version B discussion is in a section not released online.
http://books.google.com/books?id=rzXdGpkDa7YC
In my searches, I found some suggestions that this picture of the famous Senior Peg ATB design may actually be ATA Version B, but there's no evidence for that, IMO.