Can't get there from here safely or on a constant basis except with a S/C..
260 - 20% = approx 208 rwhp. Boltons ( Chip, CI, MAF, TB, Intake Plenum, Pulleys, better flowing exhaust will get you approx 60 - 80) I'have an '02 5 speed: Chip, CI, TB, Intake, Pulleys, Flowmasters installed, currently dyno'd at 237 rwhp / 277.3 torque. Have 3.73 gears as well but not sure how that works into the equation. I wish we had done an absolute baseline, but the dyno wasn't set-up at the time, we figure base was 210 something, may have actually been a lot lower. We'll be installing an 85mm C&L (or at least trying one) next week. Hoping that will push it into the 250 range. As you can see, little overall gain for a fair amount of Canuckbucks (part/labour approx $2500). And thats not including the suspension work. Headers, hi-flow cats and X pipe and new mufflers will be next on the list. (Hoping this will put into the 275-280 range which will be fine until I get the S/C installed. ($7000 Canuckbucks)
NOS will get you a 100- 150 shot but: A) You really need to do some internal work to beef up the engine B) Its really only good for racing, serves no other useful purpose (illegal on the street here in Ontario) C) Even beefing up the internals, there's no guarantee you won't break something real serious.
S/C although costly will get you close into the 350 - 400 rwhp range on a stock engine without having to do any internal work. Although it wouldn't hurt. A) On tap 100% of the time B) Its all good C) Its all good
Bottom line is, S/C it. Quckest, safest route to more HP. And that is most definitely something you and your dad can do! Plus!! You'll both be wearing shit-eating grins for weeks after first time you dyno it!!
Note, yeah I know there are a some new items out there, but the guys I'm working with don't feel they are reliable, or don't produce the advertised gains. Unless you just want to race it. Then who cares about street-ability.