I have a 1974 AM General m35a2 cargo truck that I would like to convert to a PTO driven 12' cargo dump. I have a 1975 Ford f700 with 9 foot dump bed. I was hoping to swap the sub frame from the F-700 and add it in between the m35 frame and cargo bed. The Problem is the 3 foot difference in length. I do not know how to figure how much strength the original 10 ton hoist will loose with an extra 3 feet of forward length and no other change in original sub frame geometry. I had hoped to remount sub frame and add in two 3 foot filler pieces to make up difference on sub frame. Any help would be greatly appreciated.