Re: 35 PSI in #4 CYL
Since you didn't mention excessive blow-by ..... you may be in luck (but let's not get too happy yet) and rings may not be the case. Although it happens ......in my experience ....in normal applications .... rings usually don't go bad on just one cylinder ..... it tends to be a "whole engine" condition. It's usually the same with valves ....but they tend to have more noticable effects as they degrade. All the other posts are great ..... be careful if you squirt the oil in the cylinder ... if you do it with too much zeal you may splash it on the valves and defeat your intended purpose. When you put air in the cylinder (if you do) in addition to listening at the carb and the valve cover/dip stick .... try the exhaust pipe ......and remove the radiator cap just in case the head gasket has failed to a coolant passage (which is unlikely since you didn't express any overheating/lost coolant conditions)
Side question: Bigman ...... why do you say the valve guides/seals will only smoke on start up? If it's on a intake valve the vacuum of the intake will suck oil into the intake stream. Now granted it may take a REALLY BAD seal/guide to see SUBSTANTAIL smoke at the pipe ..... but I've seen cars that put out a puff of blue EVERY time it's the bad valve guides cylinder's turn to fire.