on the TT crank, it will just use one less rib on the crank. If you plan to switch the PS pulley over to TT. (I don’t know that it would line up, never done it myself.) but the belts are the same length, the only difference is one is a 3 rib and the other is a 4 rib. K03 and K04. As for the valve covers I just tap them and install pipe pugs.