I got a boat engine 1979 mercruiser 350 with a 1409 marine carb. I need about 70 hp in my boat. I know it says it has 260hp but by the prop im sure it only has around 230hp. I want another 70hp at least out of this bad boy. Dont really want to go over 310hp. What can be done with this engine? Vortex? better intake manifold? Which ones fit and which ones you recommend? price's? Can i pull the parts from a junk yard as ive read some 350 carry better heads? Thank you very much ahead of time!

 

Best thing would probably be heads, I don't know much about marine engines, sorry.