[patrickt]

I would feel better if we could confirm our measuring marks. Eight or nine years ago, I spun my harmonic balancer inside the ring. Right after I did it, I was hearing a funny "clang," like a bell ringing, and when I put my timing light on the marks they were absolutely crazy. For a moment, I was absolutely dumbfounded, because what I was seeing was impossible. Then I took a step back and figured it out. I think you should use a TDC finder, a piston stop, in your spark plug hole, and just double check that your timing marks are indeed accurate.