Great info here.I am looking at the web page.

http://www.riley-auto.com/ADAPTERS.html

There is one listed for a 292 to TH350 for 225$.And a 312 to TH350 for 495$.
Do you guys know what the difference is.I thought the 292 and 312 both bolted up the same.
I know this thread is a little old.I did a search.