If you can find one, a 57 to 59 Ford car 9" is a bolt-in. I even kept the '49 Ford backing plates and brakes. The outside width is ok too.
91 and older ranger rears are a bit narrower( 56.5 inches WMS to WMS ) but you have to cut off the shock mounts and move the spring perches from the top to the bottom
91-92 Rangers are the same width as your stock rear end and you will have to move the spring perches and shock mounts