Assuming you are taking about M20 fitment follow the settings and jet sizes for the Monobloc carb used on later M20s as a baseline set up...It should run OK on those settings with only minor adjustments at most...Ian
This is what I have on my M21, works fine.
I mounted a bakelite manifold spacer in order to make the floatbowl go clear of the dynamo drive housing. Think it was specified as for AJS/Matchless, bought a smaller diameter and bored it out to proper size. Might have gotten it from Feked, can't seem to remember.