dumb question!!!
Mopar Performance constant output voltage regulator.
http://www.summitracing.com/parts/DCC-3690732/
I was having the same problem with a my late model 75 amp charging system. I have already done the amp gauge by pass, 4 ga wire from the alternator, relays for the headlights, as well as relay for the elec fan.
At idle (900 RPM w/ big cam) my interior lights, tail lights, head lights, would flicker. I removed the stock type voltage regulator and replaced it with the above mentioned VR. No more flicker. This is a street car not a race car so I haven't drove it enough to see if any problems will arise. Right now its working good for me.