You can plug the end of the breather hose and remove pcv from valve cover to see if there is vacuum or positive pressure at pcv hole. I think you would have to have a pretty bad leak to confirm this way.
Does it blow a puff of blue smoke after sitting overnight? That would indicate bad valve guide seals. Could be a combination of both. What's mileage? Add truck info to your signature.
Removing the throttle body would give you a better look into the corners of the intake. Four bolts to remove and a 2.00 gasket.
Compression test, wet and dry would give you some more info about worn rings.
Last edited by ReadRam; 03-18-2014 at 01:18 AM.