A while back, I purchased a Chrome Diff Cover for my 66 442. I pulled it out today to test fit it and as it turns out, it is not a 10 bolt 8.2 cover, it is too square. It may be an 8.5 10 bolt cover?, but I am not sure. The cover dimensions are right at 11 1/8" by 11 1/8". I would just like to get my money back on it, so I will sell it for $19.99 plus the ride. Please PM if interested.
Thanks,
Randy

 

Looks like a 7-1/2" 10-bolt cover to me.
I have a Mr. Gasket chrome 8.2" cover - old, but new in the box if you need one.

 

Thanks for the info. PM sent.

 

You know, I pulled out the one I have and it's shaped just like the one you pictured. Just for comparison's sake, I measured across the bolt holes:
The ones directly opposite each other are about 10" center-to-center. If measuring diagonally across the corner holes (upper right to lower left) they're just about 10-5/8". Check that against your cover, OK? I don't want to sell you another one that doesn't work for you. Mine is definitely a Mr. Gasket #3782 for 64-72 BOP 10-bolt.

 

Still for sale.