Displaying custom and varying text on multiple instances of a part within an assy

I have a question about custom properties and displaying text on parts.  For example, let's assume we would like to place multiple instances of the same part - say a valve for example.  We would like to be able to enter and display different ID numbers on these valves.  Suppose we have a part named “06106611A VALVE” that would typically be placed into an assembly multiple times. We then would like to select these valves and enter text strings (say V-29, V-30, V31 etc.) that would actually display on the valve part. 

I know we can link extruded sketch text to a custom property but I think this would be specific to all the parts and wouldn't let me enter a unique ID number for each placed valve.

I suppose we could create a new configuration and sketch text for every valve, but this seems somewhat tedious.

Any suggestions?

-Jim Anders

SolidworksBill Of Materials