Because it sounds like a diesel tractor and has the sex appeal of a watermelon-sized cold sore?
I'd almost think you were talking about my turbo mopars..
But even those aren't bassackwards enough to use a cast-iron head!
I was thinking more like SHO V6,
Now you're talkin... SHO v6 + megasquirt (plug and play available, iirc) and a turbo is pretty much the cheapest way to get THAT amount of power from any of these engine swaps unless you go to a nearly-unstreetable setup on a home-built carb small-block... which still MIGHT be more expensive.

