Converter ID

This converter is their 8" unit for a 727, up to 1992. They say this converter has a steel, not aluminum stator in it, which to me would mean it's a hard core race unit. It's stall speed, depending on how it was made could stall anywhere from 4000 to 6500 RPM.
The converter company I used to work for serial numbered all their high stalls, from the basic street unit to a full out race unit. Should anyone purchase one of our converters on the used market, if they contacted us, we could tell him the build date, the purchasers name, what is was originally designed for stall wise, and if it had ever been back in for any type of repair or re-stall.
I don't know what your end use of this converter is, but it's a crap shoot as to what it was designed to stall at. It could have been built for a small block, or big block, and who knows what stall they built it for.
I have a personal opinion of used converters. They make a great door stop. Because they're a sealed unit, you have no idea what it's like inside, and with a high stall, without information from the manufacteurer, no idea what stall. A high stall of what this one appears to be, in all likelyhood is a custom made unit for a particular application.

Hope this helps.