Just for grins today I checked the voltage output on both cars:
1966 GT-350, with mechanical voltage regulator and rebuilt alternator by Dead Nuts On.
12.8 volts @650 rpm
15.8 volts @1300 rpm
1967 GT-350, with solid state voltage regulator from Virginia Mustang and rebuilt alternator by Dead Nuts On.
14.5 volts @750 rpm
14.5 volts @1250 rpm
At least with my two cars, the solid state voltage regulator is more consistent. Not sure this data means much, but thought I would share.
Greek