that sounds about right, I would try the standard springs back in the front.
the st185 engine will happily rev to 7200.
It won't be making peak power there but you will cross the line faster if you change 1st to 2nd gear at the readline as you are doing say 70km/hr rather then 60 and you will roll further down the track at the higher speed during the time the car is not in gear.
this doesn't apply as much in the higher gears as you will spend to much time away from the engines peak power as the higher gears rev out slower.

If the microtech isn't tuned above 6500 then you may not have much ignition timing past 6500. Unless its a matrix tune the fuel should be pretty right though.