Different Axle Widths (Track widths)...??

[Rack Man]

As part of my frame-off resto. on my 70 K10, I located a later model Dana 44 with disk brakes and just scrapped my other drum brake Dana 44 axle (as it was trashed anyways)

Now that it is back together I was noticing that the front axle is actually quite a bit wider than the rear....is this normal?.....I didn't notice it before....so maybe my old one was the same.....I'm a little perplexed that the front is over 3" wider than the back....

Front measures: 67.5"
Rear measures: 63.75"
(that's flange to flange)

Can anyone shed some light on this?

Thanks, Dan

Here they are all cleaned up and looking purty!