The power to headlight: This can be a failed stator if your headlight does not turn on. Check the bulb, fuses etc, but if all look good test the stator voltage. You may find it's shot on one leg. Stator testing stuff is in the electrical section, look for a checklist by slimvulcanrider.
You can ditch the airboxes entirely with a mod known as an earshave, few different methods (pod filters vs filter up under the tank).
1986 Kawasaki Vulcan 750
NGK Iridium Plugs #7803/DPR7EIX-9
Duralast Gold ETX15 AGM Battery
Coastered & Shaved
Metzeler ME880 [110/90-19, 170/80-15]
Balance Dampers Replaced
Rebuilt Forks w/ Progressive Springs
VN750.com Grill Cover
Emgo 23-92411 Handlebars
MOSFET FH012AA R/R
1990 Kawasaki Vulcan 750
1998 Honda VFR800 FI
2014 Honda VFR800F
1989 Pontiac Firebird Formula 350