I had a TR4 A back in the day and the head gaskets were always leaking! I don't remember the option of crowsfoot heads in those days although I think I might have tried a small tweek If I had some then. I just loosened the tappets and lifted of the valve train, doesn't take long. A little tighten can reduce the leak but it didn't last in my experience. Once I tried to tighten a corner down and found that the head bolt had failed, couldn't have got to more than 20Lb foot and it sheared like cheese. As far as I remember they are stretch bolts and you can use them twice but Triumph recommended new. I'm also fairly sure they brought an improved head gasket out some tome in the early to mid 70's which should help solve those weak areas.
