I have a 383 stroker new build. Turn motor until #1 intake closed. Harmonic balancer is at 0 mark. Distributor rotary is pointing at #1. It won't fire unless I turn the distributor until the vacuum adjust can is almost touching the intake. (Counter clockwise) Never had this problem before. Can somebody tell me what I've done wrong?

 

Welcome from Florida. It sounds like your distributor is one tooth off.