We are offering billet oil caps for the 1990-2006 4G63 valve covers. Twin 1/2” NPT ports, just thread whatever fittings you’d like to use into these, 1/2” npt to -10 AN is the most common choice and eliminate your crankcase pressure. Big thanks to @mrb00st for sharing his design and drawings with us. They will include the cap and stainless bolt/nut. The original retainer/gasket will be re-used from your stock cap. These are $109 shipped priority mail in the continental USA.