Wow I feel really dumb for asking this since I bought what I thought were TW heads. But I was looking at the specs on the TFS website, and the only difference were the valve springs. The track heat heads uses the 1.46" OD dual spring setup (which is what I have) and the TW heads use the 1.47" OD single spring. But they list the 1.46" OD dual springs as optional on the TW heads, does that in essence make them a TH head? Do I have track heat heads, not twisted wedge? lol, I feel retarded.