What did they (axles) come out of?

Measure from center of #1 stud to far edge of #3 stud, thats your bolt pattern, could be 4 3/4 3" Chevy bore. You can get your A's cut and resplined. Matter of fact, your A splines may be deep enough to cut and use without resplining? They only go in about an inch. I have some Chevy 4.75 Centerlines that have a huge bore.