Action Plus vs ......... any gains?

IMO, I don't thin you'll see a big if any improvement. With 2.45 gears, the car has a lot to over come. I don't think an intake swap will net you a noticeable improvement, because you have not "maxed out" the intake you have. Start adding headers, better gears and a looser converter and then you will see some gains. All this is just speculation of course.