Guess my age! I mean mileage!!

What did the upper shells of the rod bearings look like on disassembly? I’d bet by looking at what you’ve shown that’s a 50k magnum. Nice find.
Hey! I haven’t disassembled anything on the bottom end, just changing springs porting and cam swap on it, but I might add a windage tray so I’ll have to remove a cap and I’ll post what it looks like!