The "official" ride height is published in the fasctory service manuals, as is the method of figuring it. What I find is even if the cars had front end work done, they are set too low in teh nose. The cars were almost level (except the AAR/T/As) when they were new. Dropping the nose is common, and most alignment shops take the height the car is set at when teh suspension is bolted back as the ride height. That's wrong. I know several cars that replaced the control arm bushings or used tubular A arms to get the right alignment specs, when all they really needed to do was lift the nose via T bars to get the "specs window" inside the adjustment range. You should be able to get 2° of positive caster out fo a properly set stock front end. Some cars will get more. But all should be able to get at least that. I do my own alignments too, so I can sympathize with you. If you cant get the caster past "0", the car's nose is too low or the rear is too high. It is also common for the reproduction springs to sag very quickly, or not be anywhere near the correct rating anyway. Sometimes you get what you pay for. Setting the front right, may make the back look low...because it is. Another thing, no nuts of bolts on the leaf springs, shackles, hangers, control arm bushings, sway bars, or strut rods should be torqued until the vehicle weight is on the tires. Because bushings will also make the suspension react or sit oddly. Lastly, ona mopar, caster and camber effect toe. Toe doesnt effect them. So set toe last.