Could a worn out Cam shaft effect power?

My dad has a 2004 Ford. When it was new, it had 350 Brake horse power. I don't think its lost power but he thinks it has. It has 310,000 miles on it, he bought it brand new so its been taken car of. My question is can worn out cam lobes effect power? If the lobes are not as big anymore, this could cause the exhaust and intake valves to not open as much. Is this possible, or would a worn out cam just keep the engine from running? I think my idea could be possible. He says it feels like it only lost about 50 BHP, he thinks it just from the engine being old.

Worn cam lobes are more likely to cause the engine to run a bit rougher, noticeably so at idle. If the lobes were worn enough to effect the valve opening and closing times significantly so much metal would have gone through that engine that it would have far worse problems. Decreased power is most often caused by worn rings and cylinders, burned valves or worn valve seats.

Has a compression test been done? I would assume it is more of a general wear to loss of power. @310000 miles I'm sure it has lost power.

Yeah, way past time to retire that engine. Everything is worn, cams, piston rings, cylinder walls, bearings… The whole thing. If the truck itself is OK, no rust or collision damage, may be worth a 'factory refurbished engine', which as a relatively 'simple' remove and replace probably wouldn't be too bad, cost wise.

You are thinking of the old style flat tappet cams, which are no longer used. Then yes, when the lobes wore down, you loss power. In your case 2004, its just plain wore out & tired cylinder walls & rings.

Yes, but in an engine with THAT many miles, EVERYTHING is worn and causing power loss.