This Improved Racing FO-06R is an adjustable restrictor that replaces a conventional PCV valve. Five pre-drilled restrictor plate sizes let the PCV airflow be tuned, and it suits LS engines running aftermarket valley covers that lack a built-in PCV restrictor.

Improved Racing FO-06R Adjustable PCV Restrictor Valve Features:

• Replaces a traditional PCV valve with a fixed-orifice adjustable restrictor
• Five pre-drilled restrictor plate sizes for tuning PCV airflow
• No moving parts
• Female -6 AN O-ring boss ports
• Suited to LS engines with aftermarket valley covers that have no built-in PCV restrictor; also used for turbo oiling restriction