This is the measuring device to measure the 
thickness of the metal.

The carburettor is a 32 mm Dell`Orto racingcarburettor
Type SSI-B, who is extreme difficult to find today.
It took me 1½ year to find one, but a Amal TT with the
same measures are excactly as good.

The inlet duckt shal be drilled to a diametre
of 32 mm and this area has to be held in pas-
sing valve stem guide.
You have to be very precise when you drill
and grind because there are not much metal
thickness. If you want to be safe then make
you rself a measuring device (see picture)
Then you have to make a flange and an admis-
sion pipe, which is to be grind and polished
together with the cylinder head,so there is no
perceptible transition.The tube shal have an
internal diametre of 32 mm and a lenght  of 
80 mm.