Hey BRAD :
Just something else to throw into the mix........ I did a major lighting improvement a few years ago. Have you considered using relays on your headlights? The lighting in a chevelle is OK at best due to the fact the interior and the headlights are supplied by ONE WIRE.
At night the dash lighting is HO- HUM--OK.
The one big wire that sends 12 Vts. to the inside,( dash lights, radio,heater,dome lights, cigar lighter, glove box light, tail lights) Also sends the " Left/over " 12 Vts. to the headlights.
I used two relays on the headlights with Sylvania Halogen bulbs, ( Now the H. Lights get BATT. Voltage). Also now I can use the dimmer on the H. Light switch to knock down some of the bright dash lighting.
Now the headlights are not quite, but almost " WHITE " & Bright. The dash lighting is much brighter by at least 30-40%.
I mounted my two relays on the core support, ( Ya, kant see um).
All the dimmer switch does now......... It triggers the relays.
Just ,,Something else to stir the pot !