[Overdriven]

I'm not a dodge expert, but I believe you can tune that injection system a bit (chip, programmer?) to compensate for the headers, cam, and rockers you'd need to get about 300hp at the crank. If you want more like 400hp, I'd swap in a 360 with aftermarket heads, and troll the dodge forums for what you'd have to do with the fuel injection system to support that power ie injectors, tuning etc. The easy way out would be to just swap to a carb, but there are drawbacks there too with emissions, possibly mileage, etc.

Personally I'd go in stages. headers shouldn't require any tuning and will give a noticable 15+hp increase alone and possibly better mileage. Supposedly roller rockers add another 10+hp on those engines. A mild cam that won't kill low end torque or mileage on top of these parts = 20+hp. Tuning the injection system for all these bolt ons should be another 10-20hp and shouldn't be needed until you do the cam swap.