4-5 Blown in my B18 Tranny.......

my fourth and fifth gear are completly gone in my GSR Tranny I have a spare but the mounts on the bellhousing are busted in the back where the L-bracket bolts on to the motor mount...can i just swap the bellhousing...???not the entire casing with gears but the section that hides the clutch and flywheel..????:confused: