Anyone know for sure the measurements for a first generation 12 bolt leaf spring perches to go into an 83. I measured nine inches from the drum to the inner edge of the perch on my 10 bolt and 9 3/8 on the 12. Has anyone done this before? I did a search and couldn't find anything. I am mostly just looking for someone to verify my measurements. You would figure that an Aviation Structural Machinist could figure it out. Just lookin for some back up.Thanks for any help.