I don't know what to tell you, Greg. You cannot EYEBALL TDC. That's all I can tell you. If you think you can, you're mistaken. I've already pointed out that the block must be level. I don't know how else to say it. I don't know for sure that's the right piston, but from your description, it sure sounds like it. And yes, the positive deck clearance is counted, just like a negative deck clearance is. It's confusing, because a positive deck clearance is represented by a "negative" number, while a negative deck clearance is represented by a "positive" number. The reason for this is because the positive deck clearance REMOVES chamber volume - negative and a negative deck clearance adds to + the chamber volume.