Up for sale is a 2 pack of exhaust manifold riser gaskets for MerCruiser sterndrives. The MerCruiser part number is 27-863726 and part number is Sierra 18-2849. You will be shipped 2 gaskets! These are high quality American made that meets or exceeds factory specs. We ship USPS First Class Mail for quick delivery and easy tracking. Check out my other items!