Rebuilding a 65 273..I need some help.

#315 and #080 are both 64 and 65 273 heads. Both are closed chamber with 1.78/1.50 valves.
#178 and #234 are 66 heads. Both are closed chamber with 1.78/1.50 valves.
#920 are 66 and 67 heads. They are closed chamber with 1.78/1.50 valves.
#675 are 68-69 273 and and 68-74 318 heads. They are open chamber with 1.78/1.50 valves.