The M8 sealing nuts for the oil pump cover were a relatively new development from Volkswagen in the early 1970s, replacing the plain nut they used previously. VW never produced a sealing nut for the early, pre ´67 engines and we therefore included the M6 sealing nuts in our range, to eliminate any source of oil leakage on older engines as well. These are sold individually and you need 4 per engine.