I am cleaning an abnormal amount of undercoating on my 66 K code GT differential and floor pans, I have found 622, in yellow grease chalk on hump, grip or machining marks on the tubes, i am still cleaning, should I find other markings on the housing? I am using a citrus bath to gently clean, use a rag and mineral spirits to scrub undercoat off. have used a heat gun with ventilation to soften thick spots. I am not good at the search function, never get the correct term I guess. I am also trying to find paint marks on driveshaft. 4 speed San Jose car, SCHEDULE BUILD 11/08/65.