Which is better

On the 67-72 A-bodies if you run a factory sway bar you should mount the calipers to the rear and use '69 Camaro disk brake hoses.

If you're not using a sway bar at all, you can mount to the front and use '73-76 A-body hoses. If you're an aftermarket sway bar that doesn't use the '67-72 outboard sway bar tab locations (Hotchkis or Hellwig 55917), you may be able to mount the calipers to the front as the end links will be further inboard. That may require some adjustment though.