I had to cut and box one of the chassis X members to fit the front mount in. The falcon diff mounts of the side of the pinion section.
I then made a plate to weld in to support the front of the diff. This also braced the section I had cut out. The front mounts use urethane bushes but If I did it again I'd probably solid mount it.
The back mount was easy because the Holden and Ford centers used the same bolt pattern for the back cover so I just reused the Ford Cover. The only problem was the Holden has the fill point in the back cover where as the Ford has the fill point in the diff housing. I machined the back cover to add a fill plug and put an access port in the chassis.
I have to drop the fuel tank to change the diff
oil but at least I don't have to pull the center out.
Cheers