Before you spend too much time investigating an engine oil leak, make sure your outdrive bottle/vented cap is not the problem. When I upped the HP on my 502's, it put more strain on my outdrive...the outdrive oil got a little hotter and started pushing oil out of the vented screw top on my resevoir bottles. I added drive showers and it reduced the problem but I still get some outdrive oil in the bilge.

A little bit of oil looks like alot when its floating on top of the water. check your pumps and drives or anything that holds fluid. it could be something else leakin, not the motors. I had the same problem and found it to be a trim line leakingin the bilge.

no oil

i had the same problem with my 540's,after pulling the motors 3 times and changing pan gaskets with out any luck,i found out the new merlin3 blocks are incorporating an oil drip return line thats supposed to be a for superchargers and turbochargers to lubricate the rear bearings of these units..
the location of mine were behind the sea pump brackets and were not visible to detect the leak and only leaked above 2500 rpm's, so watching it was out of the question,i dont know what brand of blocks you have but i wouldnt rule out any of the new blocks to have this galley, it is positioned on the edge of the pan gasket by the timing chain cover.. the simple solution is to clean and fill with silicone or similar but the best way would be to tap and plug

Again, thanks for the replies. Hopefully, the engine builder will be able to find in quick order. I did notice that my power steering has been using oil since the the engine change?