318 Head Headache

Make sure your car is optimally tuned. Always. This includes that the current parts are functioning as they should. Including compression check, the carb is coming fully open on WOT, initial timing, total timing, the curve, and also jetting
Next, looking at heads, I would consider the speedmaster(s), along with the others that have been mentioned. Hey, if your budget includes the TF's, by george do it! IF you go 340/360, cut them to keep the compression relevant