amp gauges

Unknown

I could use some expert advice on the charging system on our 29 model r sedan.I had the throttle stick on the floor and overeved the engine before I could get it shut down!It did not hurt the engine but broke the end of the generator shaft off,sometime in past someone scabbed the coupling on and welded it.Rather than go with an expensive replacement I am going go with a 6 volt positive ground alternator.The only problem I see is the amp gauge only registers 30 amps and the new alternator puts out 60 amps.My question is there a way to use the original gauge or will I have to disconnect it and use a different amp gauge? Thanks Doug.