Originally Posted by SomeCarGuy
You can bar over to tdc and take out distributor and look at the drive slot to see if it’s on compression stroke or not. If it’s 180 out the slot will be ever so slightly turned from being straight across. Turn over to tdc mark again and you should see the line be straight across.

haha I need to hear the logic behind this.

Just do the thumb over #1 plug hole as mentioned in previous answers. You can't possibly get it wrong,

In theory, there is no difference between theory and practice. In practice, there is.