Why does Left front wheel stick out farther than the right?

Is it commom for the left front wheel/spindle to stick out farther than the right on a 70 model? Wheel backspacing is the same so its not the rims and the car drives fine. Everthing looks identical (spindles/rotors, etc) but when you stand back 50-100ft and look straight at the front of the car you can tell it offsets outward more (sticks out farther). A friend of mine in the automotive business says this was common in 60-70 model Chevys but I'd appreciate some feedback whether anybody elses is the same? It's ironic I sold a 66 Chevy II recently with a front disc brake conversion and its left front wheel stuck out farther too. Would you guys compensate by going with more backspacing on that side? Thanks....Pat