http://store.summitracing.com/partde...0&autoview=sku

are these things just to stiffen up the leaf springs or do they act like subframe connectors????

 

Someone correct me here if Im wrong, but I believe that the purpose of traction bars is to reduce wheel hop, thus helping you to get more traction off the line.

 

Yep. Don't need them with mild street machines.

 

Yeah, they wont stop you from spinning at all. Some cars came with only one leaf spring on each side, such as Novas and early camaros. They had a bad tendency to wheel hop when the throttle was mashed. So the traction bar was invented. Multi leafs like most mustangs have dont have wheel hop as bad, usually if its hopping, you need to change the shocks or something is amiss with the rear end.

 

Here`s a great article on the subject.
http://carcraft.com/techarticles/116_0402_rear/