The valve clearence compensation problem on the intake side is solved by modified tappets. The bottom of the right tappet is machined on a lathe down to 6.60 mm thickness instead of 7.30 mm. Alfa 105 tappets (left) usually only have 3.25 mm.
The new tuning tappet (right) has 42 g. This is a 3 g saving over the original Alfa 105 tappet. Now valve clearing compensation with Alfa shims which are available from 1.50 to 3.50 mm thickness is possible in combination with reground camshafts. A good adress to find these tappets ist histo:tec in Germany or tuning shops supplying Volkwagen/Audi parts. So called "mechanical tappets" are available for VW Golf GTI or Audi 20V engines to replace the hydraulic ones to achieve higher revs. They must have a diameter of nearly 35 mm.