[sunman]

The frame brackets for those motor mounts are just a V shaped piece.
The photos of them in 15-20 year old posts are long gone.
If you have what’s pictured above for frame brackets yours are Mustang II also and not the brackets designed for your mounts which are correct for the new brackets.
I’m going to use the Mustang II mounts to locate the motor and weld up some new style brackets to fit and use the mounts like yours.