What can I do to tweak my combo?

That's pretty good with the combo you have. I'm assuming that time was on slicks.

I think your running at the limit of the 19lb injectors with the power your making. I think running 24lb injectors and a 70mm TB and EGR spacer, or an intake that makes better power on the upper end would help a little. You could also run 4.10's in the rear to help a little more.

A different cam would help a great deal with porting on the heads. There's nothing wrong with the E303 but your not going to make much more power with that camshaft. The non-ported GT40 heads are holding you back the most.

With all you have done to the car so far, I would suggest just adding 24lb injectors and dropping nitrous oxide on the engine instead. This would be the cheapest route to go faster since you've already done some motor work. Unless you are a glutten for more work/money, I see no reason to take it back apart to make daily driving suffer.

Try 16* and then 18* of timing. I'm at 16* & 41psi at this point.