front pass side, tab (ledge) from block under head, may have to clean it up to read, if ground down you can get ref of the block from back casting "behind drivers head on bell housin" IE 010 also quick look at heads be em heavy or light casting "bolts on lower head the casting gos straight across for heavy and wavy for light casting"
pull valve cover off and grab casting numbers from head..prolly diff heads but the casting will give some info...last 3 digits are all you need aka 882, 881, 487
etc etc