I don't have it done yet, but I'm planning to spool my Ford 9" rear axle when I re-gear to 4.56 for my 35's. I've been doing alot of searching and getting opinions, too, in the last month or so. Much cheaper for a 9", but I have heard about the tires "chirping" when turning. Maybe it's like if you drive slow inside a building on slick concrete and it sounds like you're peeling out? I can live with that for the increased traction I will gain in back. Most folks do not recommend one for the front with the TTB, since they say it tends to break the axle shafts and u-joints.
