My son overheated his TR 2.6 and either the headgasket is blown or the head is cracked which more than likely as there's no water in the oil, anyway I have a good head from a TP does anybody know if they are interchangable. They apper to be the same only differents is the duration of the cam and roller rockers on the TR also one is a M5 and the other is a M6 head.So would it be possible swap the cams and rockers over?