Can I use a 67 904 on a 72 225 or is the crankshaft register hole size a problem?

Agreed. I bought one from Charrlie_S recently. Same deal for small block engines too, at the same year of change.

BTW, one can actually use a 68+ tranny with a 67- engine, if you change both the torque converter and input shaft on the tranny to 67- ones. At least I have read that. There were some later trannys that are desireable (like 999).