holy volts batman!!

[67Fleet]

Got a new alternator today since my old one took a dump. Decided to get a 94amp from 84 Camaro. It seems like everything is working fine, I'm getting more charging than the previous one, and my voltmeter in the dash stays at just about 3/4 full when just off idle. My old alt would struggle to get the meter past the 1/2 way mark. I have a question though. I have a pretty lopy cam in my truck, so it idles rough. At idle my compressor for the airbags sometimes surges a little bit. Is this normal since my cam is causing the rough idle? I sure do have a lot more juice to the compressor than I did before. It fills the tanks faster now and is a bit louder. We tested the battery with a multi-meter and it read 15 volts at just off idle with my lights and the compressor running. If it's idling and I then turn my lights and the compressor on, the voltmeter in the dash moves to the right and shows higher voltage. Is all this normal?