That should have been fish plated...not saying your vertical welds aren't doing the job, but that's a BIG no no.
it's a big "works just F-ing fine" in fact
better than "fine" stood up to a terrible collision, and signed off on by a certified chassis fabricator. who he himself said that fish plates is "only one of the many acceptable ways to do it". as well as signed off by the frame specialist who repaired/straightened the frame last year.
if it weren't sleeved, it would have been a "no-no" however, vertical welds without a sleeve, would have been a seriously bad idea. as well as the fact, that sloping welds would have been a "better" idea. but not necessary.
I just wanted to show
another way to do it, that is just fine. and sleeving it made it even stronger than fish-plates alone would have.
yes I know, I
could have added fish plates
in addition to the sleeving/boxing. but that was deemed totally unnecessary, and likewise
proven (by the collision) to have been unnecessary. the only parts of the frame that failed were parts that were unmolested.
so what I am saying is that
I consulted with certified specialists, and
I have successfully shortened a frame, and
I had the aforementioned frame modification stand up to an accident that literally totaled the vehicle, and lastly
I had the frame inspected by yet another specialist after the accident, who gave it the OK.
if anyone is qualified to say what is a "no-no", or not, i'd say it is someone who has
actually done it