I commute the CRX 40 miles each way to north San Diego. It is basically stock.
Header
After head gasket blew, rebuilt the head.
new Denso plugs
Garden tractor battery
Hacksawed cold air intake into short ram intake.
Cleaned engine grounds
Replaced PCV valve and all coolant hoses
new radiator
new water and oil pumps
Civic 14" Wheels
Added AC (whew)