I prefer to stick to OEM or S&S. Tappet failure in an Evo is usually detrimental to the engine. Not always, but usually.
Stock Evo cams have a ring around the gear face. That's how you know if they're for an Evo, and not a shovelhead.
Stock cams have painted dot on them. The color determines the gear tooth pitch, in conjunction with the pinion gear on the crank.
Stock cams will have the cam model number stamped on it, IE: 1990-1999 will have "N" stamped in it, meaning it's an "N-Grind" cam. Prior to that was an "L" grind cam.
“When the going gets weird, the weird turn professional....” ~ Hunter S. Thompson~
R.I.P. Rubberdown. 1971-2012