Carriers and axles are interchangeable. Only the ring/pinion are different (reverse rotation on the HP30). However if your considering a Truetrac it will replace your stock carrier. Same holds true with ARB, Detroit Locker, E-Locker and Ox to name a few.
Are you aware the Truetrac is not a true "locker"? It is basically a Limited Slip Differential that uses helical cut gears instead of clutch packs.