I doubt if many RVers would seriously consider buying a 600 HP Cummins or Cat engine. Both engines produce 2,050 pounds of torque. A special transmission and driveline had to be built expecially for them.
There would be no advantage whatsoever for an RVer to have that much power. Way more than could be used.
I suspect that if anyone ordered a new truck with either 600 HP engine, it would cost at least 30K more than a 550 HP engine with 1,850 pounds of torque. That's a lot of money to pay for HP that cannot be utilized.
I know two guys with 500 HP tractors. Belioeve me, thats plenty more than any RVer needs for bragging rights.
I like a little overkill in the power department myself, but not enough to consider buying one of those monster.
onezman