Thoughts....for carbon buildup removal get a can of BK44 (I think) from Toyota. As far as the compression results, they are awesome. High yes...but what matters is they are even within a few PSI of each other. Cracked head wont show up on compression check until its to big to close itself....thats generally noted by a huge plume out the tail pipe. For the oil...dont be using something so heavy...the leak is there cause something aint sealing. Heavier oil will mask a problem while creating a new one elsewhere. If you are looking for backup as too the tune-up in a can should fix it idea, You're getting advice from the wrong guy <img src="/forums/images/graemlins/mrt.gif" alt="" /> Find the source of the oil (valve stem seal) and fix it, leave yourself with no worries.
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />