I've used James coated metal gaskets on Sportsters, Shovelheads, and Evos, both stock and large displacement hot rods. They are durable and seal perfectly. I've seen base gaskets from other vendors leak and even split, requiring the cylinder to be removed for replacement. Not these. They are the best there is. Other gaskets may seal and hold up ok, but there is no question that these will. Install them dry and torque the cylinders/heads to manufacturer specs. Remember to retighten the base nuts after 500 miles, with the engine hot, on engines that have them.