2.6 petrol fire engine. carb trouble

Hi I have a 1971 rebuilt Fire engine,
the stromburg 175 Cd is faulty. after hours of replacing ignition system.

six cylinder F rover 2.6 petrol

It starts but will not run for more than 10 mins
Black smoke.

Adjustment very little effect.

has anyone got a replacement for sale. or advice, can l swop it for a SU ?

These guys are helpful. Fuel Systems UK : The Carburetter Specialists

If its the same engine as the SD1 rover, and it sounds like it, then the SD1 2.6 did have 2 SU's at one time, on the same fanimold, one of these might fit.
Theres a place not far from here that specializes in SD1's, cant remember the name, but its in Freckleton.
SU's are simple to maintain, you'd be better sorting out the original if you can though.