OK, I have a 350 that's been bored out .40 and it's the old style outside bolt (valve cover) head. I've installed TBI and been running it for about 2 years now with no problems, about a year ago I installed a new cam Made for a TBI motor becuase the cam that was in there was causing me a vaccume issue with the FI. I have a TBI motor at home that has a knock in the bottom end, but the heads are in decent shape. QUESTION, Would it be beneficial for me to remove those heads, have them gone through and install them on the older style motor? It's not a built motor and that's not what I want, but I would like a little better performance and from what I've read this will supposedly help me. I have a set of shorty headers, but I want a good set like Thorley's or Elites, but I want to do this all at the same time. Thanks.