There is a U225 for sale in Wichita Falls TX. With Banks power 300 hp 5.9. they bought the 92 in 95 and have all service records + manuals. On Craigslist.
Motor home (https://wichitafalls.craigslist.org/rvs/6064597630.html)
OE was 230 HP. If 300, would be a little concerned for the 4 speed Allison-- suspect that is well over its rated HP/torque rating.
When I used Banks on my 5.9 06 I know I exceeded the specs on the RF. Took the rig to Suncoast and beefed up the tranny. No comparison with Allison but my thoughts were you mod one you probably mod 2.
The 5.9 came with a non lockup 542 Allison turbo hydro trans. Always some slip.