You can buy short helicoils, the helicoil taps are made with a few threds for lead in, after taping you can grind most of the lead off the tap and carefully tap threds to the bottom of hole, dont forget to use some taping fluid. Helicoils are considered to be stronger than a regular taped hole, so it is a good fix. Otherwise drill stripped thred out with a bigger drill, weld hole then redrill and tap with bottoming tap. Hope this helps