[sammyg2]

Set that piston at TDC, put it in 5th gear with the parking brake on and wheels chocked.
Pull the valve cover off of that side.
Hook up a pressurized air source through the spark plug hole and put air pressure on that cylinder.
Listen for the air leak. If it is going out the exhaust pipe you have a bad exhaust valve. If it leaks out the intake, bad intake valve. if it blows out from the crankcase breather, bad rings. If it blows out the head where the valve cover normally is, it's leaking valve guides.
A little leakage into the crankcase is normal, but a lot is not normal.