What are they, and are there any rear ones on the e-firestorm?

its what the suspension mounts too.... a stadium truck will have one in the front, but not always in the rear, a lot have the arm mounts built into the transmission case...

The bulkheads are not what the shocks are hooked too. Those are called shock towers. The bulkheads are what the shock TOWERS are bolted too which most times hold a diff or house a diff. One bulkhead is on each side of the diff and your a arms connect to them.