I have the opportunity to purchase a 10 bolt posi out of a 65 impala for $300. I was wondering if this rearend will fit my 67 chevelle. Owner said it was 60" from backing plate to backing plate.

the housing will not fit your car.

however, the posi/gears inside will swap into your 8.2 10 bolt.

Brandon's right. The rearend housing is about 4" wider than the one you currently have in your car. I wouldn't buy it. You can purchase a new Eaton posi unit for your current Chevelle rearend for about $300. Check out a place called Gears R Us. They sell on ebay too.