A friend has an F-250LD with the 5.4 and E4OD trans. His original drive shaft was aluminum. When he had the 2 speed gear vendor installed the new drive shaft that was made up is steel.
On my 97 F-150 the drive shaft is steel.
Maybe only the SC models had the aluminum drive shaft?
97 F-150, 2WD, Reg Cab,Flareside,Dk Toreador Red, Windsor4.6, Magnecor 8.5mm wires, Bosch Plat +4s, 3.55 LS, EGR Bug Deflector, ******* Bed Cover, Bed Liner, XL Full Length Running Boards, Air Aid Kit, Gibson Single Out Cat Back, Superchips, TransGo Shift Kit, Hellwig Rear Sway Bar, Hellwig 2500# Overload Springs