Knee deep into installing a 6BT Cummins (90,180 hp variety) into a 1976 26' Champion motorhome.Using the Allison 545 auto plus a brownie O.D. with a 3.07 Dana 70 rear.Is it possible to have to big of a cooling system.The radiator out of the bus is huge 27 x 31 x 2+" thick and the front shutter arrangement.It all mesures up to fit,really tight.Have no idea if it is way to much??