I am running a set of port and polished victor jrs. on my procharged 408 and I am looking to upgrade to a better flowing head.Mine are flowing 305 intake and 235 exhaust.If anyone has any ideas that would be great.Ihave looked at trickflow race heat but says you need costom header,is this true?They have awesomeflownumbers out ofthe box and with some work even better.Let me know I am running dart block with 7.3.1 compression pistons.Iwant more POWER