That old Offy 360 dual quad intake doesn't work near as well as the new Eddy dual plane dual quad intakes do
Are you running the linkage on your current set up as progressive or one to one?
I have tried them both ways, one to one seemed to be a lot more responsive than it was with the carbs ran on the progressive linkage, especially after getting both carbs jetted to run the best I could get them on both ways