manifold vaccum for vaccum advance ?'s

The main thing i wanna find out right now is where tht oil is coming in at. And lot of you have suggested the valve seals? Or valve guides, Some have mentioned pistons, but i dont think i hurt my pistons. i can start it up and shut off 10 times in a row and watch the exhaust and it never smokes upos start up. It only smoke when driving down the road relatively hard and backing off the throttle then the light blue smoke comes out the exhaust, and mainly only on the drivers side exhaust pipe.
I know the leakdown test will give more answers, but i have a feeling i will be replacing the cylinder heads. You guys gotta remember too this motor is 11 years old and my old man didnt exactly abuse it, but he ran it hard a fair share of times too. Granted he knew what he was doing when he worked on the engine, but he never really had to repair any hard parts on the engine its self. And this engine was fuel injected for most its life. My old man bought it as a crate hooked fuel injection too it and ran the crane cams fire ball ignition on it and ran it that way for 8 or 9 years.
The oil was always changed with synthetic and its always had premium fuel ran thru it, who knows maybe the valve seals or whatever is letting the oil by was messed up when i got the engine and i just never noticed it? But whatever it is, i will get it fixed.

i had an 80,000 mile 360. it never smoked. if youre puking any blue smoke, you are pulling oil past the rings, or the valve seals into the combustion chamber(s) and you will oil foul the plug(s). if it is misfiring from an ignition miss , then you would be pushing raw fuel out of the tailpipe(s) from the misfiring cylinder(s). a rich condition or unburnt fuel will usually show itself in the form of black smoke. by merely reading your plugs, you can find the cylinder(s) that are burning oil. they will be gooey black and wet. a cylinder that is not firing from an ignition miss will be wet with fuel and you will be able to smell the fuel on the plug.