Yank out that retarded shift kit you have and put in a Trans-Go shift kit. That should cure you short-shift problem, you've probably got some kind of shitty B&M kit in there.
With a stall converter and they valve body you should be able to run with the 5-speeds.
That 100hp shot of N2O should put you well into the 8's
p.s. All MW members BigCountry is my older brother...........give him hell
-Josh, aka the tireburner