Accu Seal Pro Steel Core Valve Cover Gaskets for Chrysler 354-392 Early Hemi and AJPE Billet 392. This product is preferred by current Nostalgia Fuel competitors for strength and re-usability with cast valve covers on Nitro applications where severe vibration occurs. New Design with Adequate Clearance for Large Valve Springs. Compare to Mr. Gasket 375G. Material: Steel Core Composite, Teflon Coated on One Side; Thickness: .087″; Package Contents: 1 Pair.