this is a smog pump from a 1973 chevelle  a new one was put on and this one  was put back in box  but never turned in for the core   spins freely  but working condition is not known   has a date code of 1019571S  what ever that is     sold as shown  ask any question  looks in good used condition not all rusty etc  part # cst into item is 7817872  think this fits  from the 1968 1969 1970 1971 1972 1973 1974 1975 era  and used on  many chevrolet models like camaro monte carlo chevelle malibu nova impala caprice corvette