oops senior moment... that number is 633 it is a gm steel shim head gasket for 283-307 and discontinued in 1997. it is .018 thick, with SMALL bore
please report any sightings to jack mccarthy
i really dont wanna spend $$$$ just because i have to change gaskets
usa3609@aol.com
502-558-3450
scooter helms call me !