There is a web page that outlines the atributes and years built for the 427SO and TO unfortunatly they dont have quantities. Check out
http://www.gessford.com/images/fordsup-33.gif Heres what they have to say about the block Apparantly some 63 and 64 engines were the same as 390 and 406 blocks with beefy bottom ends and webbing with 2 bolt mains. Some in that same vintage had cross bolts that usually apeared in low and high risers. 65, 66 and 67 were all SO's and 68 was SO withoil galleries to the lifters as these had hydraulic lifters. If mechanical lifters is retroed these have to be plugged. It stands to reason that unless ford was dumping some 64 engines that most or all the 427 cobras were side oilers