Should not be that touchy. Manual or power?
Couple of things though. The new master cylinders no longer come with pressure residual valves, even on the master cylinders that are specificed for manual drum drum applications. Factory masters all came with the little rubbber duck bill valves. So to mimic that pressure, you might consider installing say Wilwood red pressure residual valves in line for the front and rear brakes.
Are you running a distribution valve or porportioning valve?
