GS3K, 191 DV's, #10 fuel plate and 370 marine injectors if you dont mind the smoke. You might need a little more air at that point. Could even do that combo without the injectors and be close to 300.
You really need that trans done before you can really do much to it. stock trans are weak and the convertor is inefficient. I think DC did that to protect the rest of the transmission from the cummins
Scott over at mass diesel can give you some ideas if you tell him what you want to do with it and what power level you want. theyve been real good to me so far.