What a time for system updates! I decided to check if I needed a tune up - my mileage stank this last tank. I realized the timing marks lined up with the paint a previous owner had put on the circle of the timing marker. After I cleaned it up, I saw where the triangle edge is for really setting the timing. Strange! If I tried to turn the distributor that far, the cap hit the fuel hard line in the back. So I rotated the distributor innards a notch, and I can not get it to run with the timing set off of the right part of the marker. It runs fine set off the middle of the circle instead. SOOOOOO - what is the BEST way on a small block Ford, in a 1991 Mustang, to check TDC???? I am thinking, after it cools off, about taking an air chuck hold, (or an old spark plug without the ceramic in it), threading the middle, and putting in a stop bolt that fits in the spark plug hole. Then I'll get a big socket to fit over the harmonic balancer bolt to manually turn the crank with a breaker bar (so I do not jam anything) and mark it clockwise, counter clockwise, and split the difference for the real TDC. Will that work on a 302? ANY BETTER IDEAS TO SEE IF MY BALANCER SLIPPED OR WHAT IS GOING ON?