As we said, TIG welding steel plate to cast steel is not the strongest connection (welding plate to plate is much stronger). So we decided to drill and tap some holes through the plate and into thick areas of the cast housing, like along the front edge of the housing, where the differential cover attaches. Once drilled and tapped with a fine-thread tap, we can use Grade 8 hardware and thread locker as a little insurance that things will stay put, despite 42-inch tires and an estimated final 500 hp.