Admitting up front that I don't know much about current Tin Indian race parts, I'll take a w.a.g. that Big Head runs the Poncho equivalent of a KB block with B1-MC heads and a sh!tload of boost + rocket fuel. So, not "exotic" in terms of the latest innovations & architecture, but something proven and tuned to the nth degree.

Everyone else who keeps changing their combinations has to re-invent the wheel to some extent to get a solid baseline. His is probably just a series of constant refinements...