You can not put the harmonic balancer on too far. It is supposed to bottom out against the timing chain gear. Now if that balancer is from a L31 Vortec 350 and you did not install the reluctor ring, then that would account for some of the alignment issue. Have you looked at this thread?
http://www.67-72chevytrucks.com/vboa...d.php?t=632007
nearly the same issue.
BTW It is against the forum rules to post duplicate threads in different sections.