K. Smith wrote:

also take into account an engine's given horse power is always rated at
a certian RPM .

with work, you can get 400 h.p out of a small block (350) Chevy engine.
OR you can get the same h.p out of an 855 c.i.d. Cummins. but the
reliability not to mention the torque factor is about as different as
night and day.

The modified chevy turns about 7500 RPM and the Cummins loafs at about
1800.

I suppose thats one reason you don't find any small-block chevy engines
under the hoods of Semi-trucks.