I used Dick Maury’s method last night which is how I got the new readings for TDC#6.
=> Once there, using a depth micrometer or a screwdriver with your fingers, check the height of the #2 and #3 cylinders. As one is going down and the other is rising when the front cylinder is at TDC, this will help get the timing right on the money.
In the following thread Dick goes into a little more detail:
=> Actually it is #2 & 3 or 4 & 5 cylinders as the pistons are going
in oposite directions when #1 or 6 are at TDC. # 3 & 4 go up and
down together. As there is some arc at the TDC mark, a dial
indicator on #1 or 6 will only get it within a few degrees of TDC.
When the other cylinders mentioned are at the same height, then you
are exactly at TDC. It is amazing how sensitive this is and allows
a really good setting. In fact, when a car is in for a tune up, I
check to make sure the timing mark is centered using a screwdriver
and my finger. As the timing marks are adjustable, it should not be
surprising that a lot are off. Most anything adjustable gets
adjusted whether right or wrong
Jay