If you want to shoot for the early B-Body width (I would), grab an Explorer axle and do perches. The Explorer axle is already the right width. I would look at Pull and Save, there are usually 8-10 there at a time and they are only $166 + $15 core. But you have to pull it yourself.
The issue with the Explorer axle is the offset pinion, but other's have done it and probably no more than tweaking the PS muffler so the driveline doesn't rub on it.