[Captainfab]

There's no need to go to the expense of narrowing a '73-'87 differential. With a '73-'87 differential the original spring perches and shock mounts need to be cut off and trailing arm mounts welded on at the correct pinion angle. Plus a panhard bar mount needs to be either welded to the passenger side axle tube or an aftermarket one that mounts to the passenger side trailing arm.