Ok, so i know that one of the big differences between the 2.0 and the 2.5 (despite the obvious) is the cast verses machined block. So, what are the diferences between the new 2.5 sti engine and the existing 2.5 rs engine? I would imagine that the new one is machined, that being said I wonder what it would take to turn an RS into the new STI? I'm sure it's a lot more complicated than I'm making it sound, but if the main difference is the machined block (assuming that's been changed) then it would seem that (aside from the turbo plumbing) your biggest headache would be the block, and maybe the heads.... Though now that I think about it, I wonder how the RS's tranny and rear diff would appreciate then jump in power... So back to my original not really asked question... I wonder what it would take to turn my sexy RS into an even sexier STI in an RS? I dig the new sti body better than the WRX, but I still like the body on my RS better than the new STi... Guess i better start saving! Anyone know of a good mechanic who does engine swaps and whatnot in the Mountain View, California area?

 

I don't suppose you could be a little more specific than that...