I have a post in the Trans-Am Tech area looking for an O-ring that goes in between the oil cooler and the block. It is GM part #25536843. It was discontinued in 1996 and does not match the 1987 GN part or the 1992 Z28 L98 motor part. No dealer in the country has it in stock according to the inquiry they rant at the local dealer for me. NAPA does not carry a cross-referenced part either. Any suggestions? Thanks.