Manifolds

The rams horn style exhaust manifolds were used on all 58 Mercury MELs. In 59 the manifolds changed to a different style. They are conventional,no water cooling. Perhaps you are refering to some of the brochure hype about the engine touting water passages next to each exhaust ports The back cover of the 58 Merc dealer brochure shows a picture of the SuperMarauder engine. It is not an actual photograph, but an artist's rendering. Several details appear in the picture that do not appear on the actual SuperMarauder setup. This brocure was no doubt printed before the option was actually available