1995 GrandPrix GTP charging circuit voltage drops when Engine warms up

[VBChevy]

Hey everyone. New here and I figured you all may be able to assist with my Issue,

My 95 GTP charging voltage drops when the engine warms up. 3.4 liter "X" motor. I have heard that it is a bad design with the Alternator right beside the exhaust manifold with a thin heat-shield.
I read 14.7 volts across the battery with the engine running cold when first started. When warmed up voltage drops to 12.3 which is battery voltage. I had the battery put under load and it checked fine.
Wanted to see if I may be missing something before I get into replacing it, which I am not looking forward to, after reading the R&R instructions.
Anybody else have or have had this issue?

Thanks in Advance

 

[Fivefingerdeathpunch]

The internal voltage regulator could be failing when it gets hot. I'd been looking at a replacement as well.

Never done one before but youtube for some video's to see if you find anyone that has.

 

[VBChevy]

This is the R&R steps according to the manual. Looks like a project. May have to get an estimate. The car only has 82K miles, so I guess it depends on how much I want to keep the car. A youtube video on this would be a movie.