has any one gone with all new stock internals with bolt on or bigger turbo set ups....and would the stock internals produce the same or more power compared to having all new after market goodies.....most threads i read about is mostly talking about how they build there bottom block but never really their top(head)...does the head really matter a lot if your going high hp(like say 450-550hp) or just the bottom really matter most for high hp?