Small to large bolt pattern swap

Hey solid340 I'm looking for the same swap if you find rotors let me know, ECI has a kit for changing to GM rotors and calipers $575 for the kit not bad but it would be nice to just change the rotors. 73-76 show different part numbers than the 72 but that could be the bolt pattern that makes the difference. I'll post anything I find.
Thanks and God Bless Bruce