Urgefor,

Do you need the C5 and/or the bosses for a specific reason?  As I understood you were using aftermarket caps.  They are wide to allow direct contact without the bosses if that is attractive to you.

I do have a C6 block in Nebraska, std bore, pressure checked, but not cleaned or magged.  Not chasing a sale, stock for later incoming builds, but if it helped you out of a bind I'd be happy to flip

     I will check "the stacks" and see if we have one.

     But, this might too great a distance (FL. - KY.) considering freight costing?   

     Scott

Regarding the Ebay block, I must note that the block may have started out as a FT, since it has a tapped oil return hole, for a compressor. It would need to be checked for a bushing in the dist hole.

My Early 1966 428 "S" Scratch Was Cast with 4 Bolt Provisions, But, Of Course, Not Machined. I Went With The Full Perimeter 3/8" Girdle Instead Of Having The Block Finished Out For Standard 4 Bolt Caps On The Center 3 Main Bearings. It Was a Lot Of work, Was Done Very Professionally, And At Least In My Opinion, Is Superior In Strength. I will Check My Photos, And See If I Can Get A Date Code. My Understanding Is That They Were Cast From October 1966 Till February 1967. Again, Just Because I Found/Had One Doesn"t Mean They Were All Cast That Way. Seems From Prior Feedback From Other Enthusiasts, They Were Quite Rare. (Yes, This Is A 428 Block. We Installed Screw In Core Plugs, And The Obvious Roller Style Cam Bearings)

      Yes, .030" setback is generally the ideal minimum, except for "special" instances, and anything greater than .060" isn't aiding the gasket but does have other effects.   

      Scott.