Sorry to hear about the eng. How many miles on your current eng? In retrospect was there any warning signs or unusual happenings (high heat,tappet noise etc) before the failure? I guess once the pan is drop you will know better the extent of the damage. I would not be worried if they could find an 8.1 in another MH that had a fridge fire or rear end collision as a replacement, it would probably be the fastest way to get you back on the road. A 2006 or newer with the transmission would give you the 6 speed over your current 5 speed. Just another thought to consider.