repurposing axles

Is it OK to cut/weld/reuse a set of b body 8-3/4 axles for use in an A body 8-3/4 set up? I have the A body housing, backing plates and 3rd member all I need are axles and drums that are 4.5" OC. I have a spare set of B body axles that I can use.

By OK I mean is it economical and safe.

If that's OK to do then what would each side have to be in length....measured from the axle end to the back side of the flange.

Thanks in advance.

Mop