That Whitetail Hunter of yours was obsolete 20 years ago! The sight you've got is designed with very little adjustment travel for today's higher performance bows. Sights these days don't need all that much travel like they did when your bow was new.

You need to find an old style Cobra sight. The one that's simply an aluminum plate that has long slots for pin adjustment and long mounting screw slots to adjust the height of the sight bracket. That's the kind of sights we shot with back in the stone age. You might find one in the backroom of an archery shop.