Hopefully I'm posting in the proper area. I have a 2008 F150 XL 4.2L V6. I need to get cylinder one on compression stroke to TDC. On the outside of the harmonic balancer it have several marks that I believe to be for timing and a well hidden TDC arrow on the block. There's also a dot of blue paint near the timing marks. Are these actually timing marks and if so, how do I know which mark is TDC? Does the blue paint point to the mark I need? I've attached some pictures. Also wondering what the 172 and 3M7 marks are representing? Thank you!


Timing marks

TDC mark on block