Sure you mean Mustang II? because they had a rack and pinion. I've not yet heard of an early Mustang box being reversed. -KK
There are front suspensions that look like a Mustang II setup, but they have "rear steer" where they use a rack that sits behind the suspension instead of in front of the suspension like on a Mustang II. One rack they use for a "rear steer" Mustang II type setup comes from a Volkswagen Rabbit.
there is a place outta Gerorgia i cant remember the name they are building a frame and suspension for George Foreman and its a rear steer mustang II rack