73 E body front disc brakes conversion on A body. Where did I mess up?

You can reverse them side to side. Some of us mounted the calipers on rear to guarantee anti sway bar clearance especially for after market ones. You must also reverse the calipers side to side to put the bleeders at the top

I'm speaking in this case of the 73/ later A body single piston, which were factory on the front, but swapped side to side to put the calipers towards the rear. Same thing.

Also I think? the E body upper A arms don't fit? What are you doing there?