Another 318 build, and questions. (LONG)

I talked to the machine shops here around town and the general concensus on building quench into my particular combo will take some serious milling and very deeeeep pockets....so ive come to the realization that ill have to do without, and after reading up on numerous open-chamber head builds on 340's and 360's i guess its not a HUGE deal for a weekend cruiser/daily driver granted decent fuel is used, or so im told. (i run 91 in all my stuff)

so, heres what ive come up with after jockeying around numbers for a better part of my day. the heads i have (345's) cc out on average around 74cc's, so thats what i did my baseline computing with, that and ill be using fel-pro head gaskets, 4.18 bore and .039 thick when compressed. Im going to use the KB167's because they have been proven to be a great unit in many builds, and the price is right. If i have my current block (.030" over) zero decked with kb167's, and mill .030" off the heads, removing approx 6cc's, setting the head volume at 68cc's, then my static will be around 9:1, and dynamic will be around 6.81:1.

OR i could go nuts and have .060" milled off the heads, removing approx 12cc's, taking my heads to about 62cc's, and that would put my static compression at 9.6:1, and dynamic compression to 7.32:1. that i could be completely happy with.

main new question in point here that i have now is.....now much can be milled from the heads after the approximate .012 is milled from the deck to zero deck, before it starts to require custom pushrods? some sources ive found say .060", some say .030".....