My personal preference is a mini-spool...
completely reversable.. tough as nails... about $100 and an hour or two of labor.
Trail tough has them. Randy's ring and pinion has them too.
The sammy application also fits the kick.
Same as welding but won't break and completely screw your rear end. does completely away with the spider gears altogether.
Sammys are even LESS affected by welding/spools, because they weigh less. Like was said. Air the rear tires up as much as you can stand while on the street, and you will barely notice.... unless it is wet, or slick, then.......YEEHAW!!! drift city, the most fun you can have with your clothes on.
I have had a few rear ends welded, and I have never had any break... BUT, I have seen some that did come "unwelded" or in essence, broke the weld, and it sucked dude.... trashed the entire rear end. Since I saw that, I decided that a spool, or at least a mini-spool was a much better solution to a solidly locked rear.