I just got the 390 in my truck running. (gt 390). The heads were wasted, so I got a built set of c4ae's guides all felt good and tight, and seats looked good. Anyways It smokes worse than it did now than before. Before I had like 1/4 inch of play in a few of the valve guides. Its smoking out the tail pipes, and my valve cover breathers. Its got a single plane weiand intake on it. Could it be intake gaskets? Vaccumm leak? Cylinders? The cylinders looked great when I pulled the heads, cross hatch looked good. Past 4k rpm it smokes like a mofo and smokes out the cab. I am pissed what could it be.