listing these for a buddy there patriot stage 2 heads that have a little bit more port work on them complete with springs and valves. dont have too much more info on these they came with a car he bought the look like new i believe have really low milage on them. hes looking work out a deal for a 12 bolt or 9" rearend or sell for $900 possible trade for nitrous kit, wheels or other performance parts let me know what you got. they are center bolt so 99-02 f body unless you got new coil brackets and valvecovers.