I just put that same truss on a factory 9" housing that's going in my new buggy. I had to chop it up because the housing is offset, but it worked great.
I'm no pro by any means, but I took my time, and moved around to different spots welding. I checked it the best I could and I can't tell that it warped it a bit.
[ATTACH=full]145701[/ATTACH]
[ATTACH=full]145702[/ATTACH]
[ATTACH=full]145703[/ATTACH]