Is it perhaps turned around? Front edge at rear? Maybe caused by switching sides?
I think there's an inside/outside of the track the regulator pin goes through so if you swapped sides and used that for orientation you would get the front edge at the back. Whether that makes a difference I can't say.
Sic friatur crustulum
'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.