HELP! Shims question

[Andrea7]

Hi all.
I'm doing valves clearance on my speed six Cerbera and, even if I bought a shims kit from Motaclan, I don't have some size which I urgently need cause my car' engine is open.
BUT I'm writing from Italy....
So the question is: from what engine/car comes or are used speed six tappets???
I could order again from UK but I unfortunately don't have all this time...