Apparently my experience with MH engines differs from the above...
Truck engines are a vastly different breed and often the MH are lumped together with the trucks but are in fact closer related to the pass car.
The MH cylinder heads are not the same as the truck 413/440, but may have exhaust rotators (not a bad thing) and they do have better coolant passage design around the spark plug.
The cast crank in a 440 or 440 is good for about 500hp...the only issue with a cast crank is the balance.
As far as the horsepower and torque numbers go, in 1972 changes were made to the system of measuring power of vehicle engines from gross (engine only, without air cleaner, exhaust system, alternator, or other power-consuming components) to net (with alternator, air cleaner, mufflers, and other vehicle equipment installed). The new rating system produced lower, more realistic numbers for any given engine. At the same time, emissions regulations were demanding cleaner exhaust. Engines including the 440 were made with reduced compression, modified cam timing, and other tuning measures to comply with the newly-tightened emissions regulations. The 1972 440 produced 335 bhp (250 kW) (gross) at 4400 rpm; the new net rating, for the same engine, was 225 hp (168 kW)—which very closely coincided with period German DIN ratings and TÜV measurements.
