Disconnect the exhaust right at the downpipe, that should be enough. Take your intake elbow off.
Now hook up a leak down tester to that cylinder. Listen for where the leak is. If you hear it coming out at the downpipe, exhaust valve. If you open the throttle body and hear it there intake valve. If you hear it coming out of the dipstick hole, then its either the rings or the valve guides/seals.
I'm not aware of a way to tell whether it's the valve stem seals or the rings without at least pulling the valve cover off.