"The only thing a newer 6.0L and the 283 have in common is the 4.4" bore center. Mediocrity would be a relative term in this case. It seems the OP has a better than mediocre engine for his needs."
I still say the 6.0 came directly from the Chevrolet V-8's of the fifties. No? I think it is great that an engine that still uses pushrods can compete at all.
What sets the 6.0 apart from mediocrity compared to some of the other engines available today? Volumetric efficiency? Torque? Fuel mileage? Horsepower? Longevity? I say it is a mid-pack engine. I like them, and am on my third one now.