You need to know how many teeth are on the cam sprocket. If you retard 1 tooth, you will tend to move the torque curve up in the rev range. Normally, you are only looking for 2-4 deg retard to go up, or 2-4 deg advanced to get max bottom end.
According to this picture
http://www.escortfocus.com/html/escort_ ... rains.html
I count 38 teeth. That would mean there should be 19 on the crank.
If you moved the belt 1 tooth, that would be 9.4737 deg advance or retard....it'll run, maybe, but you would need to change the base timing relationship, as well.
I would think you would need to dyno, with some bushings, so that you could see what 1, 2, 3, 4, and 5 deg changes did to the power curve. This is the kind of stuff cam grinders spend years playing with, as different engines respond differently.