I went thru this two years ago. I used a corporate 8.5 rear end. There are many of them around. The corporate rear uses C clips, and a shaft seal for the axle tubes, unlike the 8.2 in your car now, which has 4 bolts to remove the axles.
You would need to remove the perches and have new ones relocated in the correct spot. Make sure end to end length of the rear matches what you currently have.
My conversion was easy, but I had a welder who has done this before. He bolted the old rear to a table, and created a jig, to perfectly match the new perches on the 2nd gen rear.
