re: TTI routing At least on the a-bodies, TTI has a modified Z bar (or you have the option of doing it yourself).
re: custom headers Performance welding if your on the west coast is worth a look and maybe a call. The website is Perfweld IIRC. Mark is no stranger to mopars as you can see on his website. Might even be have some experience with those big primaries. Stainless so less heat transfer and less rust. Price range is what you'ld expect for custom stainless.
