Derale 25720 GM Thermostatic Sandwhich Adapter with 1/2″ NPT Ports suits most USA 1963-2007 GM V-8 engines.

High quality die-cast aluminum thermostatic sandwich adapter with 1/2″ NPT ports and an O-ring diameter of 3 1/2″, this adapter provides external oil lines to allow the addition of an engine oil cooler to most 1963-2007 GM V-8 engines. It installs between the stock engine oil filter landing and the oil filter. Stock filter is retained.

Specifications:
Sandwich Adapter type: C.
Adapter thread size: 13/16″-16.
Adapter o-ring size: 3-1/2″.
Adapter thickness: 2-1/4″.
Adapter inlet size: 1/2″ NPT.

Features:
Provides external oil lines for oil coolers without relocating the factory oil filter.
Cast form high quality aluminum.
Maintain factory equivalent oil filter.
GM Type C Sandwich Adapter with 13/16″-16 thread size, fits most applications *see application guide for specific applications.
GM applications with 3-1/2″ O-ring/filter diameter.
Includes sandwich adapter, sleeve nut & O-ring.