73+ Caliper install
Just follow what the factory did and you will not have any confusion as to why some people just like to be different. Caliper location has nothing to do with the effectiveness of the braking system. Although the front location may get a little more cool air to the calipers/pads.
Disc-O-Tech
Well I guess you never install the calipers front mounted on a pre 72 A body with a sway bar or you would know they interfere with sway bar when the wheel is turned.