Just for ****s 'n' giggles this shows GD calipers bolted to V6 knuckles with subie twinspot calipers. V6 disk diameter is a few mm too big for this option.
Eunos 800M calipers have the same bolt spacing as the BA but with bigger bolts and thicker disks. HC 929 disks appear to be the same diameter and the right thickness.