Originally Posted by MADDOG
Sounds like if you are gonna tear it down, which is what I'd do, then go with a bore and stroke, increasing cubic inches.
You won't get that kind of gain from a programmer. It will require you build an engine.
A buddy of mine out here got a used 5.9L from a wrecked truck and had a local firm build him a 408 forged stroker for it. They did a dyno and he was getting about 390 at the crank with a mildly aggressive cam and MOPAR heads with some porting and polishing, a FAST fuel injection system and a B&G custom PCM flash. The truck runs great!
That'd be what I'd do. At least check your bores for wear, and if you can't spend for the stroker, at least bore your your block .030 or .040. IMO ring seal is crucial to power with these engines.