Redesigned super-strong FRONT bulkheads are narrower to get the arms more into centerline to create more traction as well as provide a much better choice of track width modification. The bulkheads have in reality actually an excellent fit on updated differential and they're reinforced to improve the reliability. The XB4 bulkheads allow super-fast & effortless diff trade and servicing by dismounting simply 4 screws through front part connected to bulkhead and base pertaining to framework. This super-fast diff access is available at both front & rear. The bulkheads have minimized ball-bearing play, causing increased gear teeth lifespan and minimized gear stripping.