408 build Horsepower estimates

Depends on who's dyno you put it on.

Why such an anemic camshaft?
Marine application, motors run under full load all the time, boats do not coast or freewheel, and the maximum RPM they will see is about 5000 RPM. In a marine application a cam with too much overlap causes reversion sucking the water that is mixed with the exhaust back into the combustion chamber. I am borderline with these cams.