Since the factory differential and pinion gears are riveted together at the factory, when installing a Sper differential, you must either put a new crown wheel and pinion in your 020, 02A, 02J, 02Q or 02M transmission or grind out the rivets and replace them with special bolts and nuts. Manufactured by ARP, the world leader in high-quality fasteners, these bolt sets are made from certified CHQ 8740 Chrome Moly material (scores well above aircraft grade). The threads are rolled after heat treatment, providing the finest threads that can be tightened more accurately without binding. The keys on our bolts are properly sized for the crucial press fit in the differential flange. We use ARP 12-point nuts rated at 180,000 psi or better. In short, you won't find a better bolt set.
