The GP have 2 dogbone mounts that attach to the Rad support and then to the front of the engine to stop that backwards movement. It has been thought of to try and adapt to a bonne but never done
I have a 1991 Buck Regal Sport with the same setup as the GP you just mentioned. I never even thought about trying to adapt it over. It'* just a mount bracket on one side and few holes with a mount bracket on the other at the front radiator support.
Time to get out the measuring tape ......