I believe in LOOSE converters, and I don't think yours is too loose. Epecially with a glide.
If the motor is still pulling good hp at 6500 rpm, leave the gear.
The place I would start would be less tire weight, same roll out, or less roll out with 4.30 or 4.10 gears.
You haven't said if your 60 fts are consistant. Are you able to run several within .01? Until you get there, it is going to be tuff to improve the combo. The current 1.41 60 ft isn't far off the mark if at all, depending on rollout.
What is the class that you run?