If you mean when both dot's are facing each other, then yes it would be 180 degrees out if you installed the distributor. When both dots are at the 12 o'clock position that is TDC #1
Of course when installing timing chain they should be dot to dot, the motor just has to be brought to TDC #1 before installing the dist.
1 and 6 are companion cylinders, both are at tdc at the same time. But companion cylinders are at compression 1 revolution apart. Stab with dots together so you can see more accurately then turn it 1 rev if you don't want to stab dist to 6 like George said.
write your firing order like this
the above and below pairs are all companion cylinders.
this is why there is a critter called a 4-7 swap cam.
you can watch the valves on 6 and know where 1 is,,,,
when the companion begins the overlap event the other cyl is approaching tdc compression. That's how I've set engine valves over 30 years now on great big very expensive engines and it works on car engines too. But with radical cams you have to let the intake move more before you are at tdc.
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