you can switch intake and exhaust manifolds between turbo and n/a as lon as you stay in the same engine familly also some internals are interchangable pistins rods cams all that jaz but the na stuf performs beter as na you wolnt make power swaping na to turbo parts unless you go turbo the 7m,s and 2jz,s have a variable length intake manifold so you dont wana swap those around some people even swap heads from 2 valve to 4 like a 5m block w/ 7m heads or vice versa search alot and you will find damn near everything has bin tried before and will eventualy answer your own question oh and celicasupra.com has a lot of indepth swap info for the m series engines
