Voltage question c40 generator/rb340 regulator

I,ve just fitted new C40 generator to my v8 mk2 …done all the correct adjust procedures etc on RB340 reg …it runs at about 14.2 volts normal but with lights drops to 13.3 in round numbers …it still shows charge on ammeter both situations and having no issues with battery so far …it just seems to me that 13.3 is a bit low any thoughts ?