Weber 32/36 DGV 5A, part number 2268000500S. It has the throttle linkage synchronised so both primary & secondary butterflies open together.

This makes it suitable for competition purposes (regulations permitting!) where the standard carburettor has to be used & power over mpg is a premium.

The pump jet is changed to inject fuel down both venturis on acceleration.

 Settings as follows:

Chokes 26/27 (fixed), main jets 140/135, air jets 165/160, idle jets 55/50, em.tubes f50/f6,  pump jet 55 (double), needle valve 200.