Check the listing for details. NEW 9" FORD 31 SPLINE TRAC-LOC SPOOL,LIMITED SLIP POSI TRACTION. Condition: New. Listed at 359.99 USD. You are bidding on a Brand New Southwest Speed 31 Spline 9" Ford Rear End Posi-Trac Spool (SWS Part #603-0381). With this unit, under deceleration, the locker allows the left rear to free-spin, while the right rear stays locked in and keeps pulling Under acceleration, it then locks both wheels back in This 4-pin unit is a clutch-style posi unit that uses several gears to accomplish this; you can see the internal parts below Features a forged steel hat and iron case with extra support in critical areas Does require the use of a friction modifier in the gear lube The ring gear bolts will have to be longer as well Also available in our Ebay store, we have: This same unit in 28 Spline 9" Ford 31 Spline Solid Full Spools Ultra-Lightweight, 9" Ford 31 Spline Solid Full Spools Ultra-Lightweight, 9" Ford 28 Spline Solid Full Spools 9" Ford 31 Spline Mini-Spools 9" Ford 28 Spline Mini-Spools GM Full Spools GM Mini-Spools We also have thousands of other High Performance Parts in our store. Shipping: There is no faster shipping on Ebay. If you pay for the item by 5:00 Eastern, Monday-Friday, we will ship it the same day. If it's after 5:00 EST, we will ship it the next business day. If you pay for the item on the weekend, we will ship it out Monday. No delays here. We want you to have the parts as bad as you do. Shipping cost will be $9.99 within the continental United States. If you buy 2 or more of our auctions, shipping will certainly be combined to save you money. We will be glad to ship internationally. Just send me a message for an international shipping quote. Accepted payment methods: We accept Paypal. If buyer doesn’t have a Paypal account, he or she can pay with Visa, Mastercard, or Discover through seller’s merchant account. After purchasing, pay instantly with your credit card through PayPal! Powered by eBay Turbo Lister The free listing tool. List your items fast and easy and manage your active items. Powered by eBay Turbo Lister The free listing tool. List your items fast and easy and manage your active items.