Agreed, I don't even think there is anything on our cars that has a 1.5 thread pitch. Just about everything is 1.25. And i've swapped the studs both directions and they thread the same.
As for the larger outer studs, they started that in May 1992 (IE 7 bolt), but I would definately rec. upgrading to it. The outer bolts are quite prone to breaking.
Wiz