look at your tac when you drive and you will see that you semdom rev past 4500 rpm,so you should make sure your mods will not decrese low end torque. if these upgrades boost torque between 1000 and 3000 rpm great if not than you ain't helping yourself .all these claims of more power are just that if they can't be proven on a dyno . so dyno it B4 and after the mods and you will know for sure. what you want to do is boost preformance in the rpm range you opperate your vehicle with out takeing away anything from the low end preformance and driveability. if you think it will improve it great ,but figure the cost of it first you may find a very small increse in preformance in respect to the cost . if you want to get serious you could start out with a rebuild with a Lunati forged stroker crank (413 cid I think) some forged pistons,the appopiate roller cam,some porting and polishing to the heads ,balanceing and so on .now those headers will realy shine . there is no end to it ,and the only thing that realy makes power is large continuious infusions or cash .
you want to have fun it will cost ,the more fun the more money .