hello gents, new to the forum. I have a question about AA leaf springs. I have 2 aa frames, one early 28 canadian , the other I m not sure of. the 28 frame has the diff attached to the center of leafs . the other frame had a diff attached to the rear of the springs with a 2 piece clamp. the middle of spring has a pivot,it would add length to the wheel base. my question is , what was this application for? thanks, Bruce