The message
from Willy Eckerslyke contains these words:

I was given a nice assortment of Triumph Vitesse bits recently. In the
box of carbs were a pair of CD175-2 Strombergs (usual Vitesse ones are
CD150s).

Some Lotus Elans (S4 with a hump in the bonnet) and +2s used a pair of
Zenith-Stromberg carbs.

According to the workshop manual these were 175 CD 2S or 2SE. The S is
the non-emisson and the SE Exhaust Emission. No idea if the lack of SE
in the query is significant.

--
Roger Chapman