Pulling my merc 540 575hp n/a to freshin it up. Just to clarify, this isnt a bully dog motor. I know most people arent aware that merc made a 540 575hp n/a motor, but they did in the late 80's. Tall deck. anyhow, I put it in at the end of last season and only put about 10 hrs on it. I'm going to put new rings, heads, cam, and bearings (if needed). I havent got into the motor yet, but supposedly it has corrila rods and a crowler crank. Sorry if i mispelled the the brand names. It has cast rect port heads. Ls6 heads #6272990. I put a 1050 dominator on it as well. victor s/p intake. The motor came out of a 42ft searay. the problem I had last season was getting rpms out of it reguardless of prop size. Im assuming someone put in some bottom end torque cam for that giant boat. It was a stump puller in my 25ft sunsation to say the least. I want to put some different heads on it and a higher rpm cam. Naturally I would like to find the best bang for my buck to to speak. I want to have a high horsepower N/A motor. Anyone have any good suggestions? Thanks in advance. Has stainless marine manifolds with custom risers i made. Dont know if i will need to go to headers.