i got a copy of a page from GM frame book & it says that the 65-66-67's are all the same & the only difference in the 68 is where the rear body mount is. there are little differences is some of the front suspension parts && the convertibles do have a different body mounting area in the center BUT other then that they are the same also. the frames are the same in lenght & width, so it looks like the 68 frame should work for him...thanks again..joe