back bench from 73 swinger in 71 scamp?

legendary just got back to me....told me the size of the seat is very different and that the covers are as well....like i said not concerned about the covers, just the actual seat fitment...as long as it fits in the stock retainers and isnt too wide or too narrow im fine (i can live with little spaces in the rear corners for seatbelts)...anybody who has actually done a swap like this or can check to see similarities/differences please help out...i would really appreciate it