Roller cams started being used in factory Fords and GMs in 1985, and they made a big jump in power -- even with the emission controlled engines. They allow a much more effective profile. And I clearly remember the talk saying that Ford and GM wouldn't be able to do it correctly, as previously it required special block machining and special parts. But it's just engineering, not black magic. It really works and now most engines have them. It's not just to reduce friction (although it does that) but to get a faster cam profile.

Quote: