Hi, yesterday I wanted to fit valve stem seals on my TR4A, a good idea because I noticed this, don't know how long this is the case. To my surprise "SU" valve stem seals have been alredy fitted, but all more tight on the stem than on the valve guide and lifted up. I fitted new ones from Elring (Germany), made for some VW engines, and of course a new spring (had a new set in stock). The tool I used to work with the cylinder head fitted I introduced some tim