What is the horsepower rating of a 3306 engine?

Depends on the set up. Is it a Naturally aspirated or turbo, or turbo with an aftercooler? And is it a Direct injection model, or a Natural Gas generator engine?

In general the 3306 has as little as 95HP ( Nat Gas Gen Set), or as much as 350 ( Direct injection Turbo aftercooled).