[Highlander]

I think you have a 9 sec car already. Just wait on better weather. If you want a better 60 with similar mph then maybe a taller tire, diff gear ratio.

If I were you I would try adding weight over the rear tires to allow for a harder launch.

 

[Highlander]

Again, make the car more efficient. It hooks already, what you need to do is reduce power losses through suspension movement and/or body movement/roll.

To reduce some of the body movement, like I said, an anti-roll bar is the way to go for body roll. You have that covered.

Can you adjust the front of the arm upwards/downwards? You will want to increase anti-squat, this usually works great in autos. Same premise that slapper bars, lift bars and slide-a-links work on.

I agree with thie above. However are you hooking without problems? Do you spin at all? Can the tires take whatever rpm launch you choose?