7 1/4 Rear End, sbp
You guys crack me up, you got to be creative. They eat those things up for the Cub Cadet and old IH pulling tractors. I sold the chunk and axles out of one of those to a guy in Wi for $125, they shorten the axles, make a few changes to their Cub Cadet gear boxes and they drop right in. Get this, they consider it a high performance setup and call it "super strong". LOL
They have a big following, heres a link to read up on what they say... I almost choked when I read it.
http://gardentractorpullingtips.com/transaxl.htm