Front Disc Conversion questions

[bmxmon]

Hey, i found a granada kit on ebay for $361. The guy is selling a couple of the "kits" Says it just like the granada switch, except i would need to switch the lower ball joint. Looking through my chiltons guide, it says i have to replace the entire lower control arm to replace the ball joint, you just cant replace the ball joint. If you search ebay for 65 mustang disc brakes, it will come up. For $361, it seems like a good deal compared to a $1000 kit, but those are brand new and come with the master clyinders, but w/o the spindles. Any thoughts would be awesome.