9.25 Rear ?

There are a few HI-PO things out there for the rear, but there not as common as a 8-3/4, DANA, Ford 9 etc...

For the most part, they came under late B body cars, trucks and vans. Today, there under Dodge Ram trucks.

For the expense of a narrowing job on one of them, you could have a DANA or Ford 9 under the car quicker and probably cheaper, probably.