If you are using a belt with marks it will take several turns for in to ever get them to all line up again. The crankshaft will line up on every cylinder that fires in its order. The cam and the distributor won't. These are meant to time only number one cylinder for simplicity!

All the sprockets rotational marks will align back again when you come back up to number one cylinder. On the compression firing stroke.

The drive key in the crankshaft should line up to a notch in the crankshaft sprocket and its belt shield. This is a TDC or 0 degree crank angle. It lines up with mark on the engine casting behind it. All these stack as a alignment.

Same in camshaft construction. The key ways are cut in both the camshaft and the sprocket. These "static marks" were placed when all of these were stopped together in a common marking location on the engine castings.

The distributor intermediate shaft has a pricked punch mark between the teeth on the sprocket face. It lines up to a groove impression at the three o'clock position of the surrounding belt cover. I use a mirror. So I can look straight down the marked sprocket tooth to see it across from the embossed grooved.

If the belt is taut and all of the above marks are aligned. You got it. If you are off. Chalk the belt over the distributor punched mark. Loosen the belt and rotate the sprocket left or right the way you need to move under the embossed groove. Counting those little black teeth will make you cross eyed! Was it the high tooth or the low one of the belt?

If it was done the right way before? Then your ignition timing will be spot on when checked with a timing light.

Hope this help your and others with questions.

Phil