Well remember, 318 guys are always citing " budget" I figure if I need the 360 heads why not look for a whole engine....? I do realize the value of a closed chamber aftermarket aluminum head though on the 318 . I personally would not grind and port a 318 cast iron head unless I could flow test it get numbers and match a cam and that sounds like more money thus killing the budget ...the problem with home head porters is it's for bragging rights no one proves if there are actual gains.