Sierra International Exhaust Manifold Gasket Set 18-4398 Exhaust Manifold Gasket Set For: gm 181 (3.0L) cid eng; 140 HP S/n 3332137-6229717 Mercury marine 27-53354a1, barr mc47-27-53354a1, GLM 39300, mallory 9-61405 Without Siamese port cylinder Backed by sierra's industry leading Warranty