[Mgs] Excessive Voltage?

[Daybell7 at aol.com]

Greetings MG'ers,  
 
I've installed a generic ballast resister in my ignition circuit and  
voltage is correct while the car is not running: 12+ volts & 6  volts.  When the 
car is running, I measure 13+ volts on the ignition  side of the resister 
and 11+ on the coil side and at the coil.  Is this  correct?
 
Also, does the voltage regulator affect the operating voltage of the car  
generally, or just the charging system?
I thought voltage throughout the car should not exceed battery  voltage, 
i.e. 12.6V.  
 
Thanks in advance,
Steve Hughes
Gainesville, FL
MGB 1972
MGB-GT 1968
TR6 1973