I've had my 8.875, 3:31 posi, since 1981. Even back then, forget expensive, they were impossible to find. If you could find one, they were about $1.2k to $1.5k, incredibally stupid money back then. I got it tossed on a horse trade for a '64 Chevelle SS vert I owned. And the rear was the real motivating factor for me to ditch the vert, even if it were a Chevy!