Yes that is certainly the best idea. And just yesterday I found that the milling costs would be prohibitive. So that plan has been buried unfortunately. If I could get it done for under $300 I would do it but when taking the milling of the intake side into consideration it really doubles the cost. In my small city, it is all rather limited what we have available and here, it is almost unheard of to mill the intake side of the head (which to me is just common sense). The standard practice is to plane down the intake to fit. Easier for them they say, as it is easier to set up on their jigs and most jobs would be aluminium too. Other options to increase CR are a 0.020 copper head gasket in addition with new flat head valves (stainless). Compared to the OEM tulip shaped vale head. Over $700. Or use the money for a port job. Which I will start making enquiries about this week. I have a die grinder and some experience with port matching but that's all, not sure if I would be confident in tackling the runners and comb chambers and needing to get all even CC volumes. I have done reading about the methods and where to use the die grinder, but in practice, it's a different story. Even if I put on Edelbrock RPM heads, those CC are 63, which would reduce the CR even more.