If you are determined to go NA then optimizing the cam could offer you some benefit.
However, if you look at the bang for the buck you will likely find it's a poor return for your money. Just a guess but $750 for cams, for say 10-12 rwhp is a reasonable guess. For all we know the cam isn't the restriction at all, the heads could be the true restriction to making good power past 6500 RPM. Truly, I hope I'm wrong. I hope cams become cheap and offer a lot of hp gain for the 3.8.
Tex, are you waiting until a cam is available before you build yourself that new 4.2 stroker motor? What are you going to do for tuning? Will it require larger injectors as well? I'm eager to see your results as I'll compare the cost/ hp of the 4.2L vs. the cost/ hp of a turbo kit.