Welding a back brace on a 8 3/4, any advice??

I’m about to try welding a back brace on my 8 ¾ and I need some advice. I’ve done some reading, and most folks agree that the right way to do it is to use a jig to keep it from warping the housing. Well….I’m a backyard mechanic, so I don’t have a jig…but this was my thought.

What if I tack weld a piece of angle iron on the opposite side of the housing from the back brace, and leave my axles and spool installed…would this be enough to keep the housing fairly strait if I space my welds (to not build too much heat) and work my way slowly around welding the brace?

Also, dose the brace need to be fully welded all the way around?

Any and all advice is appreciated,
Thanks in advance

Edit: Forgot to add...and when finished (obviously) cut the angle iron brace off the front.