Oil Pressure Check Valve Back to Mopar Index   Oil Pressure Check Valve Used in flathead six cylinder blocks to regulate oil pressure. The original design was flat on the end and seated in a tapered passage. This improved design has a rounded end which fits more securely in the passage and does a better job regulating the pressure.   New plunger and spring, 1934-42 $26.80 New plunger, 1946-54, 21/32" diameter $28.60