The Detroit is a fully automatic locking differential, if you need a dependable locker, that only unlocks when you need it to, the Detroit is a good option. 187SL17B is for 31 spline axles.
FORD 9" Detroit Locker 31 Spline. DET 187SL17B
Optional Next Generation Rear 40 Spline Assembly.18 months of design, engineering and testing, resulted in the industries strongest 40 spline rear assembly. The design completed rigorous FEA testing and analysis. - Forged chromolyspindles, hubs, and axle shafts - Forged spindles have 4x more yield strengththan 35 spline spindles - Hubs with over 80,000 psi yield strength to match the spindles - Tone rings integrated into the hub - Forged 4340 chromoly 40 spline axle shafts that are 55% strongerthan 4340 35 spline axle shafts
Fusion Elite Kingpin 60 Front Axle Standard Features:
72" width for ideal steering geometry and tire clearance when running 40" tires. Other width available or call for custom width.
High clearance center section with custom low profile fabricated differential cover
Genuine Made in the USA Spicer® 10.1" (256 mm) ring and pinion gear
3.5" diameter x 7/16" wall axle tubes
Lifetime Warranty US Made Chromoly axle shafts with 1480 solid u-joints
Massive, race inspired Kingpin inner knuckle Cs and outer knuckles, no ball joints to wear out
Fully machined springless steering arm attached with 6 ARP Studs
Steering arm upgrades available for full hydro or virtually any application
1/4" plate axle bracketry designed to be the strongest in its class
8 x 6.5 bolt pattern
Massive 13.25" brake rotors and dual piston calipers