Thank you Butch.
After looking at several different paths, we're going to use a T101A with full REM processed internals that's got fresh dogs, with a Tex SR1 and/or my Jerico top loader as back ups.
We're also going to run the Winters quick change in the 12 hour enduro in October, and assess things after that to make a judgment about whether it will last 25 hours. For what it's worth, both the transmission and rear ends will be set up with identical cooling/cleaning systems consisting of a scavenge filter, a two stage Mangus belt driven external pump, a dual HP4 filter boss to both increase fluid capacity and filter the fluid, and an 11 x 11 plate cooler that's got fresh air ducted to it and a fan pulling air through as well.
Also building up a rack that will mount on top of the hood on the hood pins for lights, since we will be running in the dark as well, and a wiper and defrost system.
Purchased four sets of wets the other day.