I've never had problems with the AutoZone plastic washers at all and they also have replacement oil plugs/bolts as well. So for a total parts investment of less than $4 plus the oil you can determine whether or not you need to monkey with the pan. Simple. If your averse to a Fumoto installation, do as Chopper suggests and chase the threads. Just remember that there is a difference between a tap designed to chase/clean threads and one to cut new threads. These are simple solutions for a simple problem, too simple to be sweating pan replacement.

If it does come to that, pan replacement is simple also. Just make sure you have a new gasket and a torque wrench as it's all to easy to over-torque and consequently break pan bolts.