I raced GN and Ocean boats back in the 68-73 era. I worked for Holman Moody Marine. They had the best cast alum oil pans and oil coolers made back then for the Ford FE engines.
http://www.ebay.com/itm/Holman-and-M...item1c3d0bf109
I ran a Rayson Craft with a 468 Ford and later a Mandella with a 460 Chevy. We used an oil pan made by Tom Davis at Aviad in the Chevy. Most guys running a Chevy or Chrysler used Aviad or Keith Black. Aviad is still in business, but Tom Davis has left us.
We never used water pumps, just water pressure. I know if you are pleasure boating you need a pump. Some oil pans on race boats had copper tubing silver soldered inside them with U bends outside the pans. Water went through the tubes before going into the engine. Object was to cool the oil and heat the water a little. It worked real good in the old days. Not much different today in boats.