Quote:You do if you want to screw an SU carb on one, but if you are asking if anybody makes one, then the answer is no, ... well not for a single SU & there's a good reason why.

A single SU manifold is a solution desperately looking for a problem, ..... & it's a problem that doesn't really exist in a commercial sense.

Why do you want to run a single SU carb on a small Datsun engine?
If it's for economy, then a bloody good tune up & the correct driving style will yeild wonderful results in a stock 1200.
If you are looking for a modest power improvement, then either a dual barrel downdraught Weber carb on the original manifold, or a fabricated adapter that connects the SU to an original manifold should do the trick very nicely.