Borderless: In-game windowed (not borderless), VSync off (for unlocked FPS), quit. Edit %LOCALAPPDATA%\EA Games\Dead Space 3\system.txt. Window.Height & Width = your PLP resolution (no border *), Window.WideScreen = true, Window.FOVScale = 1.05 (ie crop off legs, keep butt). ShiftWindow (+ border = borderless & to position).
OR Fullscreen (unconfirmed but logical): use SoftTH (DX9 x86), in-game select resolution.
(PLP screenshot with bezel effect)