OK, there's a 99% chance it's an a998, which is a lockup 904, but they mostly had lower 1st gear, and 5 clutches?

If the data tag has an A36 code (trailer towing), it'll most likely be a 998.

You'll have a better chance getting what you want in vans and trucks. the old 79 300's had a nice 727 set up in them.