What's the difference between FD and FC rear calipers?
 

I have a GSL-SE rear end that I couldn't get rear calipers/brackets for, so I decided to upgrade to the Big Brake Kit that uses FC rear calipers and rotors. As I currently have it in my custom application, I don't like how the FC caliper has two bleeder screws, and to point them up for bleeding requires me to pivot around one pin that will make my ebrake rotation not work well (for my application). So I was wondering if FD rear calipers might be an improvement. For one thing, they appear to only have one bleeder screw per the picture I see on rock auto, and for another, they have two bolts that mount to the bracket instead of the one pin that is covered up on the FC caliper. This looks like I could swap L/R easier if necessary to make my ebrake angle good. So, first, will an FD caliper and bracket mount in the same place as the FC? If not, will the FD caliper mount on an FC bracket? If no to both of those, would an FD caliper bracket fit well over an FC vented rotor if I made a different size bracket to replace my FB rear BBK bracket?

Appreciate any info anyone has. It would be great if one of the local parts stores had one of these in stock so I could compare to the FC caliper.