my friend has a f22a6, and we're looking for a spare head to practice porting, if it comes out alright we're going to put it in his car, along with a regrind, and port matching etc....please, i know all of the other stuff that should go along with a ported head.

anyways, my question is....could we buy a different f22 head other than an f22a6? I mean are they interchangeable, and does the f22a6 head have any advantages other that the IM?

thanx