T4 question

[Tony Z]

As far as heads go, Oliver will help you the best. From what I have heard, there are a new set that are soon to be released. For a turbo application however, the stock heads, with a little work should be more than good enough. If you are keeping the stock 94mm pistons, you shouldnt need to go bigger than 42x37 on valve size, then clean up the ports. If you got 103mm pistons, you might want to go up to 46x40 valves. Remember that a turbo forces the air into the chamber, as well as makes more power than a normally aspirated engine, so the head work does not need to be as radical, which allows you to keep some more strength in the heads wich will be needed for the extra power.