EMP 57-57504 Riser, Exhaust Replaces Indmar: 53-2009, 53-2018, BARR Marine: 20-0102, HGE: HGE 2018, Quality Mark: T-20907, Sierra: 18-1907 and fits 302 and 351 Ford based Engines. Port and Starboard. Engineered Marine Products (EMP) is the aftermarket leader in delivering superior parts and accessories to the marine industry for over 40 years. EMP is a premier supplier to Original Equipment Manufacturers for both production and replacement service parts. EMP has earned a loyal following by providing the highest quality products for a wide variety of engine brands. No other aftermarket company is more committed to the level of quality, performance, protection, and all EMP Parts are backed with a 2-Year limited warranty.