Years ago I had a cottage industry shortening housings and shortening/re-splineing axles. IMHO the only correct way to shorten a housing is with a bar all the way through both sides of the housing.

Even with the bar installed, after the welds cooled, the bar wouldn't easily turn so I would have to heat and shrink the housing into alignment. Admittedly, I'm not the best welder but lots of experience showed me that ANY welding on a housing will result in warping it.