Dodge Spirit overvoltage and CAM check

I am working on a 1993 Dodge Spirit (2.5L not multifuel or turbo) as a daily driver for my daughter who is living at home and going to community college. The car runs very well except for two problems:

1. The dash voltmeter consistantly runs one needle width above the inner normal mark (confirmed by a multimeter across the battery posts while running at 15.8 V). The alternator was replaced about 4 months ago, and the battery last year. I do not recall the dash gauge reading so high before the alternator was replaced, but it was always near the top of the inner normal mark. I can pull the alternator and have it bench tested at the parts store, but I suspect it will check out OK. I read on another post on this forum that there might be another voltage regulating circuit in the computer control module. Is there a way to check that out? I already traced the ground cable over to the body and cleaned the connection to bare metal, with no change in voltage reading. The battery negative cable has three heavy gauge wires. One goes to the alternator frame, another goes to the fender as mentioned above, and the third dissapears into the plastic sheathing of a wiring harness. Any ideas as to how to fix the over voltage condition?
2. There is a pretty loud lifter noise at startup and under light throttle acceleration. A mechanic's stethiscope while producing the noise by blipping the throttle from idle confirms the noise is on top, not low on the side of the block. My current strategy is to run some Rislone in the oil to see if it is just a sticky lifter. Again, I read a post on this forum about the 2.5 L four having cam/lifter problems. How would I go about checking the cam for wear? I do have a 6" sliding caliper with dial gauge. How much difference in lift would be OK?