Scarebird Disc Conversion Caliper Direction

I have been in the process of installing the scarebird kit on my '70 dart swinger and am not sure which side of the spindle the caliper is supposed to go on. The old instruction sheet I got (which was from 2007) says for the 10 inch drum set up that the caliper opening is supposed to face the rear of the vehicle but their website seems to contradict that.

Does it really matter what side the caliper goes on? Everything seems to fit with the caliper opening facing to the rear. Will it interfere with anything if set up this way?