Stock E-body dash lighting sucks as everyone here knows. If you leave the stock lenses in place, I don't think you'll need to worry about dimming them. I've got cheap LEDs from eBay on my Dart dash. You might be able to find cheap replacements that fit the Challenger wiring as well. Some of those LEDs are rediculously expensive. Just try cross referencing the stock bulb number to an led on eBay.