I never thought to count the freeze plugs. DUH!.... I dont remember there being any letters on the head flange, but thats not to say that there arent any..... I'll be back at the shop tommorow afternoon so I will double check then. Now heres a stupid question; if this is a 305, 307, 327, or a 350 nut is not 100% I dentified as such, would the main and rod berings all be interchangeable? Im sure they wont be, but its worth a shot in the dark. Thanks again Everyone!!!!