Front or Back??

Yes, the 73-76 A Body single piston calipers came from the factory, mounted to the front.
The 65-72 Kelsey Hayes calipers were mounted to the rear.
On your conversion it really doesn't matter which way you mount them, as long as you use a rubber hose that works for the caliper location, front, or rear.
I have universal flex hoses on there now. Had to put a turn in them to gettem' to fit. Will this be a problem? There are no kinks in the line and all clearances are good when turning the wheel
.