TY for the info.

Bolt hole to bolt hole, 3 3/4
From bolt hole to inbetween two holes probably 4"
Found already made aluminum 3 bolt adapter flange yoke, but it is for bolt hole diameter of 4.3"
Since they make them they could drill to the right diameter.

The pilot bushing would just be making sure the adapter is centered like a hubcentric spacer for our aftermarket wheels.