The supercharged MR2 centre would be 7"????? maybe(can't measure - over the other side of Sydney).
The diff is being used in a chain drive application and as the chassis pickups, diff mounts and assorted sprockets have been fabricated to suit this particular centre, I'm trying to avoid any unnecessary expense.
As to power, I would expect somewhere in the region 170~180hp and the vehicle weighs in the region of 400kg.