Voltage regulator gets pretty hot?

I put a Petronix electronic ignition kit in my '51 Chevy around april. Since then, the ammeter almost pegs the + side usually but not always, and it is always right around 3/4 of the way to being pegged. turning the lights on or the blower motor will cause the needle to retract a little but normalize where it was.. Just to see ( and because the old 1 was orig ) I put a new voltage regulator on it. Ammeter still pegs sometimes but rests around 3/4. Voltage is solid at 7.3v ( car remains to be 6v ) so that seems right. Car runs fine, nothing seems out of place except when I checked the temp of the regulator, it was pretty hot to the touch. Is that normal for a Generator voltage reg? wiring is not hot, just the tin cover and I would guess, the entire case is pretty hot.