How important is the backing plate? Would it matter if I chose not to replace it even though it is very worn. I grinded a ton of it off and took some of it off that was rusted. Does it serve any functional purpose? 1986 GMC Jimmy 6" springs 3" body, 38/15.5/15 Swampers, 14-bolt FF rear, Dana 60 front, 1991 front-end.