If you are running the short 13s, and a stock cam/head class you might want to stick with the 3.67. If you are running stock diameter 3.94 it is.
Get the diff crack checked before welding. Also after. I have only seen one break, and it appeared to be due to cracks that were there when it was welded.
Don't turn the wheel much when backing up or you WILL break outer CVs. Otherwise it has not proven to be hard on parts for me.