These will help you dyno the highest numbers. Lightweight wheels/17" rims w/according tires + 4.77 will help with acceleration.

Teamrx8 dyno'd 220rwhp on a mustang w/cobb tune (not exactly what you get with the Accessport) while retaining full emissions and no CEL's, search his username...

Staticlag also had some great NA mods but made less than team. Lower potential inherent in engine or mods not as effective? Hard to say...

You know, too much emphasis is being put on HP here. You didn't buy the 8 for its straight line performance, so why are you throwing so much money into that one aspect?

Buy some springs, strut towers, sway bars, and good tires. That will make a HUGE difference, and then you can save the rest of your money for a good turbo. Get a good cat-back if you want more of a muscle-car sound.

Racing Beat Ram Air Duct
Racing Beat Rev8 Intake
AP Pulley
Some form of computer modification (whether it is an accessport or RB flash)
RP Supercat
catback exhaust

You will be lucky to get +20 to +25 WHP, but that's about it. You can lighten up other stuff, but 50 hp is not possible on NA mods. Don't waste your money on Greedy pullies, as AP is cheaper & gains of all of them are around 1-2 hp.

Testpipe will stink up your car, throw a CEL, make it unbelievably loud (especially with a Greddy cat back exhaust) and gain over hi-flow cat is about 2 hp (on an NA car).

If you want about 50 hp, get the Zex Nitrous kit with 55 hp jets. Only way to do it on the cheap.