yep..thay are just done right sick..if i had the money and if winberg could convert my billet crank to work in a ls1 block i would do it..the l92 heads come stock with a 260cc intake runner..u give that head to some one like curtis at rfd or tony at b.e.s and they would flow over 400cfm at .700 lift and around 270cfm on the exh side more then likely