I don,t have the answer,but I recognise these problems!
My carbs had different weights of dampers and my brandnew fitted diaphragm was leaking....I put in new jets and now it,s working acceptable.
Biggest change was installing a brand new,complete electronic distributor,not cheap but working so much better!
An other change was connecting a new tube from the valve cover to the inlet so it had no leaks anymore.
Maybe this will help somehowe