Despite the nearly 100 percent used-parts quotient, reassembly went smoothly, as evidenced by the ideal gear-tooth contact pattern and on-spec ring-gear backlash reading of 0.008. The only shock we discovered while disassembling the spool-equipped 489 unit was that the 12-ring gear bolts (which have lefthand threads) were bottomed out and not fully clamping the ring gear to the spool. It seems the aftermarket spool’s ring-gear flange is thinner than that of the stock Chrysler Sure Grip (0.389 vs. 0.401), creating a situation in which the stock Chrysler bolts become too long and bottom-out in the gear. Besides munching the threads, the bottomed-out bolts delivered a bogus torque reading and were not fully clamping the ring gear to the spool. It’s a recipe for disaster. The lesson: Check all blind holes for proper fastener engagement when parts are being mixed and matched.