Yes indeed, Nigel. I have a rather large assortment of valve shims for a multitude of differnt cars and motorcycles that use them, being in the business as a mechanic and shop owner. The ones used in the Ferarri were reasonably easy to access once the cam covers were removed, and using a set of cam follower or bucket depressors, feeler or clearance gauges, a sharp pick, magnetic pick-up tool, and digital micrometer is all that is required to adjust the valves. In the case of the aforementioned Ferarri, the moniker "Quattrovalvole" meant that there are 32 valves in the V8 engine. If you are lucky, only half of them will need attention.