Had many vehicles over the years using SU carbs (e.g. Rover, Jaguar) - Now I read about some similarities between SU's and slide carbs; but SU's design being simple and elegant - unlike slide carbs, like on FZR's!! https://en.wikipedia.org/wiki/SU_Carburettor
I still have some 1 1/4" H4 (HS4?) from Mini/Morris Minor if you want to make a manifold and try them.