I believe you can use sections of it. It will be longer, of course, but it also gets a little different up near the Trunk and C-Pillar area, if you would be buying a full quarter. I would also ask the vendor though to get their opinion, as well as other opinions on Impala sites, if no one else jumps in here.
-Parting Out over 75 '58 to '73 Full Size Chevy Cars-
-National Impala Association
-Vintage Chevrolet Club of America