I drive an ITA240 and my obvious competition is the CRX.

I finally have the car to a point where I am very happy with how it handles and brakes but I am getting toasted on the straights.
Luckily there is lots of room for improvement but I need help deciding where to spend the pennies first.

I have:
Stock block with lots of miles.
Near stock head. Recently had all new seals, valves re-done and port matched. Not plained since it was dead straight.
Stock manifold, port matched. 2-1/2" exhaust.
Stock ecu and gears

So some obvios choices are:
Rebuild the bottom end, do I go .040 over?
Plain the block or the head a bit.
Header
ECU
4.6 gears.

My home track is fairly tight. Mostly 3rd gear. 4th gear most of the back stretch and some of the front. Into 2nd for one corner. No 1st, no 5th. Not sure if the gear change would help or not since I would have to use 5th on the straight.

If you have a suggestion, sources and prices would be helpful.

Thanks
Corey