Originally Posted By feets

The big coaches can have the industrial type engines instead of the engines used in passenger vehicles.

The pre 1972 and earlier Class A motorhomes and HD trucks had the industrial 413 which had a bunch of special H.D. parts in them only found on them.
The 1973 and later 440 motor home motors, Class A.B and C had either the 440 low compression vans and pickups motors in them or the 440-3 with the extra exhaust valve cooling passages in the heads and blocks, no other special parts shruggy scope

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)