Hom much should I have milled on a set of gt-40 with a 64cc and a NA 306?

[bjl95mustang]

I'm doing a budget build with a stock rebuilt 302 .30 over pistions an performer intake and a set of 351 gt-40 heads with a 64cc chamber (i just checked them) and a tfs 1 cam and 24 lb injectors. I'm going to stay NA for a while and i'm trying to deciede on how much to get milled off of the heads to get a decent cr. Any help would be great.

 

[rd]

I milled my iron GT40s .020 inches. I may do another 10, but it is probably best to deck the block also. Next rebuild, I am going to zero deck this block.

Mock up your block and measure deck clearance, and you will probably be amazed at how much is is.