Rear Differential - your help appreciated

[truckster]

I have a 72 Blazer with a 12 bolt 3.73 posi that just sent some of its guts out the back cover. The flange on the carrier where the bearing goes broke off. So now I have the top off the Blazer, the weather's nice, and I can't drive it.

The local 4wd shop says they can build me a 10 bolt for $900, but that's more than I want (or can afford) to pay. So what are my options? Cost is definitely a factor; so is time.

The Blazer sees some off-road use, but it's not a hard-core wheeler. It's mostly my daily driver.

Thanks for your help.