mini tub pictures

Hate to start this forum again but if any of you get this I messed up big time. In a state of hurry I ripped my old rear out of my 70 dart without taking any measurements before I put my 8 3/4 in. Do any of you have any measurements I can use to put the new one in? I am mini tubbing mine out as wall and relocating the leafs to the frame. Any help would be appreciated