[paw2000]

All the different manifolds will work with enough effort applied. I just couldn't see bolting 75lbs on the top of the motor, and with all that mass the additional heat. On a boat thats using raw water cooling, 70 degree water is being circulated and water cooling is much more effective than air to water we use in radiators. There is also a lot more options for throttle bodies for the HSR, and like most hot rodders we all like the glimmer of new,different performance goodies. I was also understanding that boats run a consistent throttle position, usually 3000 rpm after its up on plane. A boat doesn't coast. let off the throttle and is slows down quickly. So a manifold for a boat might be optimized for a particule rpm range and prop size.