I havn't done a comp test or leakdown yet but my car is puffing blue smoke when I shift. I'm not loosing alot of oil, maybe 1/2 a quart every 3000 miles but my car is smoking in low and high rpms. I know my gaskets on the vavle cover need to be changed but would the spark plug gaskets puff smoke when I'm shifting?

Also, is there anyway to diagnos a leaky valve guide or valve seal without pulling the head?

 

Need to start from top to bottum....There are gasket on the valve cover the prevent oil going into the chamber...Tighten your head gasket a bit more, to be safe...Most likely a head gasket problem. If you want to avoid goin into that, try one of those engine restorers. It should help, if the problem persist and/or gets worse take it in to get fixed.

 

Leaky valve cover gasket isn't going to let oil into the combustion chamber. It just drips oil outside of your engine. Smoke's coming out thru the exhaust pipe, right??

If compression or leakdown test is good, then suspect valve stem seals. You get the strongest manifold vacuum when you close the throttle to shift, so it sucks oil thru the valve guides. The valves are closed during compression or leakdown test, so you don't see this.