It can happen after any plug work. The issue is, especially on the earlier engines, there is only like 3 or 4 THREADS of ALUMINUM in the head the spark plug screws into. It does not take much torque to strip the head. I have heard of a few spitting plugs out, but I know for certain that on Dad's truck it was caued by a plug change. I would say, look up all the info you can, and go "by the book". Treat it like you ARE going to strip it out and be gentle, and you should be ok. I do know they make heli-coils for these, but I have heard of varied results with those......