Proper bevel, proper weld, that notch in that car will never fail. If you really wanted the added insurance at the weldment, the scab only needs to extend a bit past the joint, like an inch or two. Something that big is just extra time, work, and materials.
I feel ya! I figured it was for beefyness. :number1
Want to talk tank like construction… Check out the Duramax van we built an 6 link cantilever setup for. 1/4 wall errrrrything! LOL there is atleast 150lbs of steel back there!