I need to improve my 60' time.

My best and only recommendation would be... real slicks. Know any stock eliminator racers? They usually have 9"slicks that aren't quite fast enough, that can be bought reasonably, and still get plenty of laps out of.
And in my worthless opinion, the proper place for a pinion snubber, adjustable or otherwise, is the round file. If your rear body lifts, and plants the tires like it should, any pinion snubber should be waving in the breeze, the added weight just slowing you down.
Improve your sixty two or three tenths, your quarter times should improve double that.
Also, imo, nittos are not nearly in the same class as Hoosier or Mickey drag radials.