<font color=purple>Well, 34X9.50's were specifically designed for Jeeps & Toyotas. And they work exceptionally well. The Q's are probably a bit better overall in general just because of the increased diameter, however you might have better luck turning the 34's with a stock 22r. And really, a good racing tire will make a great general mud tire - for the same reason. The only exception to that is that sometimes directional tires (like Boggers) aren't as good for generic use since you have to back up sometimes on trails - while you don't in competition.
Your 5.29s will probably change the characteristics of your truck quite a bit. Buddy of mine had 4.10's & 33X12.50 TSL's & said he couldn't spin them hard enough to make them work properly with his 22r. But, you might be able to spin Q's with 5.29's. I really can't say.
Both are exceptional tires. And I almost went with the 34's this time around, but didn't want to give up too much tire speed (didn't want to have to regear). You really can't go wrong with either. Don't know how tall your truck is, but if you can fit the 34's but not the Q78's, definitely get the 34's & don't worry about a lift. But, if you think you can fit the larger rubber, you might have to think on it.
As to welding the rear, I'm not a big fan of that because of the reliability issue. Especially if you're getting new gears. I'd be more inclined to do it on a stock diffy that could be replaced easily than to weld up a new set of 5.29's.</font color=purple>
[img]/wwwthreads_images/icons/wink.gif[/img] Got Mud?
G.U.M.B.O. Mud Racing