Allison Man.. I have a 1999 30' 165K miles Blue Bird shuttle bus I will convert to a Class A motor home. It has a pusher 5.9 24V Cummins with 4 speed Allison auto-trans and I don't have the model #. Appears that the trans has been recently rebuilt and has Dexron III oil. This increase in weight plus pulling a 25' IO boat will require me to boost the HP output 50 to 80 HP. My questions are what can I do to add longevity to the trans. First I will add a trans temp gauge so what should I expect the normal operating temp to be? I see gauges full scale 250F and others 400F what should I use? Would you recomend a synthetic oil also? Thanks for what you do. Big Hartz