A little on the slow side.
A 2.3 60' is about right for the E.T., but you should be trapping about 3-5mph faster (depending on weather and mods). My car trapped 100mph on 28" drag radials (far too big for a bolt on GT, even with gears) in 90* heat with 90 something % humidity.
Another thing, what's the elevation of your track? The higher you get the slower you go.
Of course, it could just have to do with needing practice. It's amazing how much time quick shifting and knowing exactly when to shift will shave down an E.T.
I wouldn't get discouraged though.