This is my opinion of them, great for drag cars and pro streeters, not so good for everyday drivers. First off, if you are using the original leaf spring setup, you must also install floater brackets on the axle housing. If you weld the bars solid to the rear housing, things will bind up and break. They can be welded solid if you are using coil over suspension. The most important thing is getting everything adjusted correctly, pinion angle, bar positions, rear end alignment etc. It is not as simple an operation as it looks to be. However the mfg. of these set ups do send detailed instructions with them. If you like a challenge and learning exsperience, go for it, along with about 500.00 or more. They improve launch and traction immensely, but can also be real squirrely if not adjusted just right. Jeg's, and other parts source's list them in ther catalogs. You will be happy with them, especially if you are using high HP and torque engine. Otherwise, traction masters or Cal Trac's will also do the job.