Strange timing bracket. Application?

The only reason for all this is I'm putting together a '68 340, and it would be nice to have the timing marks in the "correct" place. I have the pre-70 style balancer, but all my chain covers are the newer style. I believe discharger 1332 still has a '68 cover for sale w/o the tab, which is the piece I haven't been able to find yet.