There is no way you can just put dual calipers on you're car and that's it. The only ones that will fit are f-body's. Wich also require F-body bracket's....wich also require them to be drilled and tapped.
That along with the purchase of some new rotor's for the F-body cars.
The kit's that I sell are a simple bolt on solution to far better braking. You will not belive the difference. It's definetly worth every penny. And you can save a little money by buying with me since I have the cheapest kit's around.About 50 bucks cheaper to be exact.
If you're intrested or have any other questions be sure to ask. I'd be more than happy to help