Tommy, Bobby, thanks for the help - I'll definitely take you up on it.
I'm almost positive that I want to weld the tubes. The entire point of the upgrade is to make sure that I don't have any rear axle issues. I'd hate to leave a potential weak point and have an issue on the trail.
There are some pretty good threads on welding the tubes:
"Welding the tubes keeps them from spinning. It's done as a precaution to make sure this doesn't ever happen. When welding the tubes, make sure you do them about 1 inch at a time. I welded on one side, then made another weld 180* on the other side of the tube and kept doing this until the whole tube was welded, this helps keep from pulling the tubes up or down due to the "warp" that welding can cause. A lot of guys pre and post heat when they weld the tubes. It was about 100 degrees the day I did it and all I did was weld it up and let it cool naturally (no water, compressed air, etc.) and everything went well. I also welded up another 8.8 for a guy with a MIG using the same process and it turned out good as well."
"I welded the tubes to the housing with a 220V stick welder and 6011 rods."
"Pre heat it first and use a 903 I think or 908 rod and you want to heat the weld again. And have some clean sand to cover it to let it cool down very slowly. Ask what rod at a welding supply store. you ant to do it right getting cast that hot can make it very brittle and shatter. one inch at a time 180 out but you can do both tubes flip and do both again heat and dump sand or a thick welding blanket to let it cool down slowly."
There was a lot more advice here, but it's all over the map.
My takeaway is that it isn't that difficult, and there are many ways to get the job done, and it doesn't need to be perfect or the prettiest welds to be effective. I need to get the axle all cleaned up first, which may take a while. Thanks, Stan