This is the third season on the engine re build. Engine started as a stock 2004 Merc 496HO and was built to 625hp NA three seasons ago.
The crank bearings are now the Dana Clevite 77 'H' tri metal (copper and lead matrix on steel backing). The heads are the iron 496 heads with new bronze valve guides and spring loaded Vitron valve stem seals.

The first season 36 hours oil analysis was copper/lead of 13/5 ppm

The second season 59 hours oil analysis was copper/lead of 199/10 ppm but a new Hardin Marine 3x18 copper&bronze oil cooler had been installed which likely contributed (so I thought) to the spike in copper disolved in the oil from copper oxide contained in the new oil cooler.

The third season 67 hours oil analysis was copper/lead of 261/8 ppm.

Previous three seasons oil analysis was copper/lead of 10/3, 35/10, 48,16 ppm all with the same OEM bearings made of aluminum metal marrix ie no copper or lead. After the first season the heads were replaced with the current heads with bronze valve guide sleeves and the spring loaded Vitron valve stem seals.

Where besides the crank bearings can copper come from and show up in the oil analysis? I am asking this because there was no increase of lead in the oil that would be expected if the copper increase came from the bearings.

did you try testing the new oil first?? are you sure your not getting a bronze reading instead of copper. are the rispins full floating? does the block have bushings in the lifter holes? some valve spring shims have a copper coating on them..

+1 Bronze and brass are copper alloys.

Yes tested new oil. Yes the oil analysis detects the copper regardless if it is from a pure copper part, brass part or bronze part or what ever. Do not know I pins still floating since have not opened the engine up. No bushings in the lifter holes. I have been using the valve spring shims with the copper coating since the new heads were installed way many seasons before this. However I did replace the springs this season and these shims were reshuffled then. Possible.

pull a valve cover and clean the top of the valve spring retainer,,but a paint dot on each one to see if the valves are rotating..this may be where the copper is coming from..

Cam bearings are also full of copper and have a very thin babbit surface.

Main thrust bearing?

Cam have a copper thrust bearing, behind the gear?

No

I'll go along with that..