It is Klotz. They say so in one of their video's of a truck having major work done. I think they rebuilt the Diesel, replaced the Turbo and installed a lot of Gale Banks goodies. They mention directly that they partnered with Klotz. I am 100% sure on the Klotz not on which episode though!
I can not think of anyone in the last 20 years that has publicly contracted with Red Line to make an oil for them. I am a Red Line fan boy too.
I remember saying to myself when they announced that "Oh a lotof East Coast Porsche Clubs like Klotz in old vintage engines and gear boxes especially the ones that would show up for SCCA events especially the vintage guys!
Klotz is a well company to anyone that has any historical background in the automotive world of collecting or racing vintage cars. It is at least as well known as Schaeffers and Cenpeco. They are old companies, mostly regional and into vintage cars and minning operations. Before what 2 years ago no one heard of HPL before! You guys ever heard of Standard Oil, Union Pacific, Wolfs Head, Cenpeco, Schaeffers, Penrite, Fuchs???? Not every company has a shelf tag at Walmart but that does not mean they are nobodies either. Like wise a rebuilder's warranty should not reflect on the oil. I am not sure of any engine builders that do not require the same thing.