Rear Brake Caliper positioning. Help

[68firehawk]

I haven't been able to find much info on the ideal position of the rear brake caliper, so here goes.

I'm currently working on mocking up my rear axle. It's a custom full floating 9" with 12.5" rotors and Wilwood calipers. From what I've seen most rear calipers are usually put on the upper rear corner or near the 1:00 or 3:00 position of the rotor.

Can anyone help guide me on this topic? Pro's, con's or ideas on why they might be better in one spot vs the other?

Thanks
Jake