Check out Rockauto.com
They have a conversion axle kit with axle, bearing, studs, and seal for $99 each. Shipping is extra.
You should have the short axles 31.313".
You will also need the 5 lug drums from a 72.
https://www.rockauto.com/en/catalog/...le+shaft,10439
You can also find a coupon code for 5% off on the internet.