Well Ive always heard that the spindles will not interchange for b,e body to the a body but i have 70 e body discs on my 71 scamp ... had it on there for 4 years now never a problem still have the same tires too with no unusual wear and my car tracks and steers great... so maybe there is a geometry snaff foo but it hasnt bothered my car... now for putting 73 up a body discs on the older e,b's ive seen it done and no problems