Not sure, not had the head off one yet! Must have a look at the poor quality CD I've got, for interests sake. If the tappets are shim adjustable, suppose we are looking for that that lever down tool to compress the spring as I used some time back on my Lancia engines. Like I said, not sure but will look at the drawing, got a feeling they may, may, be hydraulic. Catch you later. Unless someone has posted an answer already.