Why use OEM versus the cheapbay gasket kits? For starters OEM fit and finish on the gaskets is second to none. The majority of the materials used are vastly superior to those economy aftermarket replacement sets. Where those kits will use a paper gasket that will work one time, and then require scraping to remove, the OEM Toyota gasket is a rubber coated stainless steel gasket that is often reusable. The aftermarket kits typically aren't as all inclusive as the OEM Toyota kit either.