Suspensions, whether A arm or twin I beam, are a set of compromises. The twin I beam was developed because Ford wanted an independent front suspension without losing the indestructible features of the I beam(forged beams and king pin). It was an inexpensive way to get an independent front suspension. The trade off was simplicity and cost, versus front camber issues and expensive alignments. The flip side is A arm suspension gives a better ride but also has it's maintenance issues. I've had Fords all my life, and they can be tough to bring into alignment. Sometimes you can bring them in but they usually won't stay that way. The offset bushing they use can frequently get it close but not spot on. Personally I've never owned a twin I beam that didn't wear the tires on the outside, even after an alignment. I just accept it.
