The console amp meter is only +/- 40 but the alternator is a 100 amp from March. American wire talked me out of wiring it when I did the 69 camaro. Is there a gauge I can replace it with ?? Any ideas??

Get a volt meter, it actually does what the ammeter should do.
And that is tell you how your electrical system is doing.

The '69 factroy gauge is a milivolt meter, not an ammeter. It registers the change in voltage in a 10 ga. wire (I think) from the junction block behind the battery to the horn relay.

The '69 factroy gauge is a milivolt meter, not an ammeter. It registers the change in voltage in a 10 ga. wire (I think) from the junction block behind the battery to the horn relay.

Exactly.

1. I don't think trying to indicate a 100 amp charge will hurt it.
2. The odds of that alternator ever trying to put 100 amps into the battery are pretty slim.
3. you could upsize that charge wire from10 to 8 gauge. That would reduce the gauges reading considerably.