340 Rear Main Seal Install with Superformance Seal?

You spread a thin layer of sealant on the mating surfaces of the main cap? Definitely not a professional building practice. They are machined mating surfaces for a purpose. Ever hear of cap fretting?

Anyone building a motor at home please do your research and follow sound building information and practices, not keyboard samurai warrior's using youtube video's and harbor freight weapons of mass destruction. Do it right or do it twice.