you have to buy the heads..plus they are bare which will require springs...valves and probably guides..
I would buy a set of Engine Quest heads..EQ...small chamber like a 302 head...bigger ports like the X heads..better combustion chambers then X heads....flow alot better then a X head...
and probably cheaper went all said and done...you can get them with the LA intake bolt pattern...and just go to junk yard and get rockers off any magnum engines...