I haven't seen any posts on headwork on this or other FFS Forums. My experience with headwork has been great. Although it's been with American V8's. Some Mustang 2.3l have had headwork done with great results. Faster spool-up, better et's etc. Head work seems to be complimentary to forced induction. You know that if I'm going to go thru the effort to upgrade my Turbo's I am going to pull the heads, with not much additional work.