Comp's XE Cams
David Vizard states that some cam companies such as Comp.and Lunati offer nitrite hardening for their cams as an option. He recommends taking them up on this for the extra price of $100 as of the writing of his book; How to Build Horsepower. Obviously I would expect this to be more now, like everything else these days. Other than **** and abuse that seems to be freer and more prevalent.