Are these heads worth buying for $150 for a 455 build or would I be better off waiting for a set of 6X-4 to come around? What is a reasonable cost for milling them down a few cc from 101 to around say 95cc, again worth the milling cost or wait for 6X-4's? Any of you local Canadian guys had any of this type of work done lately? Cost? I am somewhat aware of the intake match issue for too much milling.