Want to see what people think, I have a friend looking at a boat with solid roller lifters in the motors. He doesn't have time to check or adjust himself, so its me or he pays.

The cams have a gross lift INT/EXH of .707/.715
.020 tappet lift of .281/.294
Advertised duration at .020 (I was used to .050) is 281/294
For what its worth lobe center 112, dry exhaust.

Question running most of the time 4000-5000 rpm range is how many hours for checking?

I have not had solid cams since my old flat tappet muscle cars, then motorcycles. And my last bikes were all Desmodromic so those were a whole different animal. But I do like that setup.

BTW
Down here 100-150 hours a year is pretty normal for us.

at first,I'd go 10hrs and check,,if things look good,,go 20hrs,if things look good,go 25hrs and stay at 25hrs for checking.anf if you can get an on engine spring tester,do that too.
I check the merc 1075's in a couple of OL's at 25hrs and most times they are fine.the idler pulleys make it easy to tell when its time to go thru the valves.when its jumping,time to adjust,most times is nice and steady.