The guys are on the right track. For years I couldn't get it into my head that when the timing marks on the timing chain were lined up THIS WAS NOT TOP DEAD CENTER, so I would drop in the distributor, and it was 180 out of phase every time. Became a running joke in the family that I "did it again."

Hold your finger or thumb over number one spark plug hole and slowly crank the engine till you feel compression blowing it off. Watch your timing mark, and bring it to zero. Drop your distributor in pointing to number one plug. This will get you close enough to fire. The fact you are hearing popping is a sign the plugs are firing at the wrong time in the cycle.

Could be other stuff too, but you need to confirm this first.

Don