Corzette...... I realize it may have been a long time since you wrote about your question but I have had this same problem for years. Please tell me if you have ever found the fix for it. I have the same Damper FLU-716242 bought from summit. I did all the checks you did finding TDC, used the piston stop, rotate the crank back and forth then haft of that TDC lines up with stationary at TDC, it checks out but when I start the car I can't get the marks to come down to the stationary mark. One year I tore it back down to see if the timing chain was right and it was , then the next year I tore it down again to make sure it was right and it was, this is how bad it has me confused. The funny thing is the marks line up at TDC but after starting I'm 50 degrees off or so. I was so surprised to see your question about the same thing, but at the end no fix ! Please write back with what you did.