Sounds like your making some decent power and torque so my suggestion to you is if you want to run the numbers at the trak, invest in a set of ET Streets...I know alot of people love their drag radials and run good times with them, but for overall consistency the ET street is the way to go. It also sounds like you are somewhat of a "newbie" to the track scene (PLEASE don't take it the wrong way!) so the ET streets can be more "forgiving" if the car is launched too agressively. 3 years ago I was running 2-3 tenths quicker than most stangs with exact same set up but only b/c of the tires and my agressive launching....I know a big concern with slicks is the durability of the rear and axles, but from the amount of $$$ you invested in hp already, I would feel safe to say that a few extra $$ shouldn't be that big of a concern for you....just remember all the hp in the world ain't crap unless its applied to the ground properly!!
P.S. suspension setup is very important as well but for a quick fix, the slicks will do the trick for now...I was running 1.7's 60fters with TOTALLY stock suspension