Any info on installing tapered axles in a 64 8 3/4?

The differential is exactly the same. A "diff" is just the 3rd member, even using the slang it's not the whole axle.

Serious mansplaining there. I think we know that lol

..... I'd be inclined to shorten that housing, weld on new housing ends and get rid of the tapered axles and brake drums and make it a more manageable width all at the same time.
Me too or just find an A housing