I think mooneye is right, I seem to remember these as being rated at something like 275 HP, but that could also be for the 383 engine. We didn't do much with the Chrysler marine engines at our Marina, but they have a reputation for being good, dependable motors.

I would think all the normal car hop up tricks would work on this 360, so a decent cam, ignition, aluminum intake and carb should get you near the 300 HP mark you are looking for. I'm sure some of our Mopar guys on here can offer some insight into those mods.

Don