Back in 2000 I had N9 cams fitted as part of engine upgrades, the original cams have been boxed since then. Now I'm installing 536 cams and thought I'd compare the OEM and 536 cams. I was surprised to see that the OEM cams were of the HCR type, my understanding has been the HCR cams weren't fitted back in 1998 as standard. Anybody shed any light on this?