If putting a sapph bar on a 3 door, then you will not have the location pegs in the right place on the amrs as sapphy type mount on inner side of arm and 3 door on outer side, massive difference in bar length.
So either fit sapphy arms or weld on a location point for the arb drop link.
Then you would need to weld a bracket to attach the main arb mounts to on the chassis type but that runs across the car, just above and rearward of the diff, very worthwhile mod though.
I had cossie 3 door arb on my xr4i and there was so much movement from the rear it was unreal.
tabetha