A matched pair of 1966 Impala, Caprice, Bel Air, Biscayne, 396 427 Big Block Exhaust Manifolds. 3884504 RH Right side dated C-28-6 (March 28 1966) and 3892307 LH Left side dated C-23-6 (March 23 1966). Over all excellent condition. The exhaust studs on the Left side will need to be replaced and rilled out.