15 years ago there wasn't so much out there for conversion kits, so most of us had to use doner car parts. I remember back in the day removing the entire rusty front spindle set up brake pads and all and installing it saying good enough. May be lucky to be alive, wasn't such a good idea thinking back. I think today like anything else you get what you pay for. Yeah you can buy a used set of calibers, rotors, spindles and it all will work to a greater or leaser exstent. Did you think the granada had a great factory brake set up, that's what you would be building. I think going with new parts makes a lot more sense and you would hope a kit is set up so all the parts work well together. Sometimes I do wonder thou, how great these kits are. In my head if you put great big 4 caliber brakes on the front you really need to do something to the rear to balance out the braking power or you've created something unsafe. Unlike most I have opted to sick with four wheel drums and make sure they are set up correctly, this included new rubber brake lines and high qauility shoes. They stop better than most disc conversions I think. They are however drums so will have more fade after repeat hard use.