I would like to hear from anyone who has posted their G heads. Did you find it necessary, or for added insurance? My target static compression ratio will be 9.5:1/w DCR of less than 8:1. I'm hoping to get there by either zero-decking the block or having pistons .005 above deck, using flat-top pistons/w no valve reliefs, milling the G heads .021, and using Best composite head gaskets. The 292 block is now + .060, but I hope to use + .075 pistons (3.825) if the block passes the sonic check. Needless to say, I don't want to deal with head gasket failure down the road. 

How beneficial will it be to step up from stock 7/16 to 1/2-inch head bolts/studs?

I have found no benefit to using ½” head bolts versus the original 7/16” bolts providing grade eight 7/16” bolts are being used.  Early on I did do the ½” head bolts for the high performance Y’s but that created other issues when porting the heads with those heads drilled for the ½” head bolts.  All the 600+HP Y’s being built now are using the 7/16” head bolts with the long bolts being torqued to 75# and the short bolts torqued to 70#.  The bolts being used are ARP.

With a zero-deck block and 0.021” of head mill, the intake manifold is expected to fit without any additional machining.  This is assuming the decks were only milled 0.020”.  Any more milling than this will require 0.014” of intake surface mill for each additional 0.010” of deck and/or head mill.

Adding posts to the ‘unposted’ iron ECZ-G heads gives some additional insurance against head gasket issues down the road when retaining the stock compression ratio.  I have had first hand experience with ECZ-G heads that were milled 0.050” and those had head gasket problems on both banks in a very short period of time.  By the book, Ford originally said no more than 0.010” milling on the unposted ECZ-G heads but that value is being pushed out to 0.020” total for ‘G’ head milling with some of the ‘G’ heads not cleaning up at the aforementioned 0.010.  Anything more than the stock compression ratio with the G heads will mandate using posts in both locations in both heads.

Lorena, Texas (South of Waco)

Vic, I sent PM.

Here are links to some of the past threads on this site that discuss posted or posting of the Ford Y cylinder heads.

Advantages of posted heads
Posting G heads (how to)
Posting G heads (tutorial)
Which cylinders to post 

Lorena, Texas (South of Waco)