stripped threads in simms pump

[terry274]

The threads in the drain hole of the Simms fuel injection pump are stripped on my Super Dexta. I used a Permatex® Stripped Thread Repair kit to repair it last year, but it is time to change the oil and I am expecting problems when I drain the oil. When I repaired it last year, I could not get the oil to stop dripping out the hole, and so the threads did not form well.
I need some suggestions for a more permanent repair, I am considering a heli-coil insert but that requires drilling the body of the pump, which I am very reluctant to do.
Terry