the 8.3 liter in the case now is topped out the l10 and M11 would give you the horse power and torque needed for tough conditions gears in pto house would have to be changed l10 runs 2300 high idle no load, not worried about the l10 holding up have 8500hrs on 9150 case now, changed mains and rod brgs @ 6000hrs old brgs were still in good condition, uses 1qt oil every 30hrs good engine!!!!!!!!!!!