as big of head as you can get big block CID needs big block air.. 225 AFRs TFS High Ports that are CNC and flow 340 cfm or so a set of the CNC Edelbrock's Victor Jrs or even the Victor heads if you got the cash or even a set of Yates heads how much do you want to spend? What is the purpose of the car?? With that CID and a proper set of heads to feed it and get the most out of it it is not gone to be cheap but then again the set you have is not cheap. Also what pistons do you have and what Heads do they accept??