I added short boxing plates in front of my 10 bolt on my '50 3100. I've moved my shock mounts inside the frame rails. When prepping the frame for blasting, I removed the old rear upper shock mounts. I noticed that the frame was slightly concaved behind them. May have been due to rust although the frame didn't appear to have deteriorated...there was however "scaling" rust between the mounts and the frame. It was hard to tell which it came from. I suppose the shape of the frame in this location could possibly have come from stress...just guessing. I weighed the issue of the plates vs. a potential weakened frame in this area.
