Charging Issue, Sporadic charging voltage Options

[slapshot]

I've been unable to figure out why my charging voltage is so sporadic. Charging voltage ranges from 12.35 volts to 16+ volts. I first noticed this 2 months ago but it could have been going on since I got the car last November. I've tried 4 voltage regulators, the one that came with the car (after market), an original VR from a 74 1.8l and two different models from Transpo. The issue is the same with all VRs, with the voltage jumping around as RPMs change. Today I started it and the voltage at the battery was 12:35 with the car running. Voltage did not change as the increase RPMs while the car was still parked. When I took it for a drive I saw it was over 14V then later it was over 16V. Voltage does lower to the expected amount (< 14B) when I turn the head lights on which puts more load on the battery. I've redone three grounds, the one above the transaxle in the back, the one under the relay board and the one under the fuse panel under the dash. Has anyone else experienced this?