Depends on which shafts you upgraded to. If you have the 1310OE ones, then carrying the factory ones as spares is not a bad idea. If you changed the flanges to yokes, then a field swap is not exactly going to be easy, and carrying some spare UJ's is a better idea.
I have the 1310OE shafts and carry the stock ones as spares along with a couple of 1310 UJ's. I would continue to wheel with the factory shafts, plenty of people do. If you have an auto, you will likely lose the boot off the front one soon enough, but it will still allow you to enjoy wheelin' for the rest of the day.