It's a T170 or RTS, see link below. I did my own conversion using this transmission last year. The difference is night and day. The ability to make quick synchronized shifts maximizes your hp enough so you can drive in normal traffic. Being able to downshift saves on your mechanical breaks.
The OD gives you more top speed while lowering you limited RPM's and prolongs engine life.
http://www.fordgarage.com/pages/Trem...20T170FT%20RTS.