Should be no problem at all. I replaced my 1980 Fuji BB with a Shimano BB UN-52 68/xxx where xxx was the width. I used a different crank and rear hub than you'll have so you'll have to figure out what the correct width will be but that shouldn't be too much trouble.
it sounds like your crankarm is bad, not the bottom bracket. what exactly is "stripped?"
The bolt that goes through the crank arm and screws into the spindle had "backed out" during a ride and when I got home I noticied the threads on the bolt were pretty badly damaged and the bolt would no longer screw into the spindle. I took the bolt to the local hardware store (one of those really old places that has everything) and they were able to provide a replacement. It screwed right in so the spindle appears to be fine, it was just the threads on the bolt that were damaged. I added a lock washer so hopefully the bolt will not "back out" this time. What would be causing this?
trek 520 & 736, DeRosa Professional, Fuji Professional, Raleigh International 3-speed, Saronni (any info people?), Humber 3-speed, Raleigh Sports, Carlton Grand Prix coming soon!
non-drive side? can't speak to as why the threads on the crank bolt are bad, but the fact it spontaneously backed up is highly suggestive of a bad crankarm. the bolt was probably not torqued tightly enough to begin with, and the crankarm worked its way loose, ratcheting the bolt out along the way. once this happens, the taper on the crankarm is almost always ruined, resulting in a repeat event if the bolt/crankarm are reinstalled.
if it appears the crankarm and bolt will take, you should re-torque the bolt after a week or so of riding. otherwise you need a new arm.