{"product_id":"arp-rover-3-9l-4-6l-v8-with-10-bolt-heads-head-stud-kit-arp157-4301","title":"ARP Rover 3.9L-4.6L V8 with 10 Bolt Heads - Head Stud Kit - arp157-4301","description":"It is for good reason that virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition powerplants. Simply stated, there’s not a better stud setup on the market today.  For openers, ARP uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi. This procedure ensures complete heat penetration and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.  Following heat-treat, each stud is centerless ground to make it as close to perfectly concentric as possible. This procedure involves about ten very slight cuts and results in an exceptionally straight part. It’s important to note that lesser quality studs are not even centerless ground – the material is thread rolled in bar stock form (mostly before heat-treat, when the material is easier to machine). Because ARP studs are manufactured to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly aligned – something that won’t happen with inferior quality head studs.  ARP studs are thread rolled after heat-treat, which gives them about 1000% (that’s ten times) better fatigue strength than those studs that are threaded prior to heat-treat (a very common industry practice). It costs a lot more to do it this way, because it’s tough on tooling, but the results are well worth the extra effort.  You will also note that ARP offers specially undercut studs for several engines. This procedure (done only to the shorter studs) more equalizes the “stretch” of both studs, which makes for a more consistent clamping force – and one that compensates for head gasket compression when the cylinder heads are installed. This helps prevent blown head gaskets, and assures optimum engine sealing!  Premium quality heat-treated 8740 chrome moly steel head stud kits are available for most every domestic and import applications.  You won’t find a better quality stud on the market from any other source. Look for ARP stamped on each stud as your assurance of quality.  Clearly, ARP Head Stud\/Bolt Kits are the best on the market today, and the favorite of leading professional engine builders in all forms of racing.  *HIGH PERFORMANCE SERIES* High Performance head bolts are available with a reduced wrenching hex or 12-point and wide area flanged head that eliminates the need for valve train removal to facilitate cylinder head retorquing. All High Performance Series bolts are 180,000 psi (which is 15% stronger than Grade 8) and kits come complete with hardened parallel-ground washers.  *PRO SERIES* All Pro Series bolts are cold-forged to ensure molecular integrity, heat-treated prior to thread rolling and machining, and are rated nominally at 200,000 psi. ARP Pro Series head bolt kits are application specific – designed for use with typically competition only components. These fasteners deliver superior strength and meet the ARP “ZERO defect – ZERO failure” quality standard. Hardened and parallel-ground washers are included with each kit to ensure even load distribution and accurate torque readings. All Pro Series head bolts have a reduced wrenching hex or 12-point head and wide area flange to eliminate the need for valve train removal for cylinder head retorquing and permits the use of larger diameter valve springs. Most applications have undercut short bolts that can help eliminate head gasket failures through providing more “stretch” to compensate for the additional compression of gaskets.   *Head Studs vs Bolts* On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, it’s probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car.   For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing powerplant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment.   Studs also provide more accurate and consistent torque loading. Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode – never crank it in tightly using a jammed nut.  If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run.  PartNumber : arp157-4301 Description : Head Stud Kit; 12Point Head   1993 Land Rover Defender 110 Base V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1994-1995 Land Rover Defender 90 Base V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1997 Land Rover Defender 90 Base V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1997 Land Rover Defender 90 LE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1998 Land Rover Discovery 50th Anniversary Edition V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1994-1995 Land Rover Discovery Base V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2003-2004 Land Rover Discovery HSE V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1998 Land Rover Discovery LE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1997-1998 Land Rover Discovery LSE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2003-2004 Land Rover Discovery S V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1996-1997 Land Rover Discovery SD V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1999 Land Rover Discovery SD V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1996-1997 Land Rover Discovery SE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2003-2004 Land Rover Discovery SE V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1996-1997 Land Rover Discovery SE7 V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1999-2000 Land Rover Discovery Series II V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2001 Land Rover Discovery Series II LE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2001-2002 Land Rover Discovery Series II SD V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2001-2002 Land Rover Discovery Series II SE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1997 Land Rover Discovery XD V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1995 Land Rover Range Rover 25th Anniversary Edition V8.4200cc Engine Components::Head Stud \u0026amp; Bolt Kits 1998 Land Rover Range Rover 50th Anniversary Edition V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1989-1992 Land Rover Range Rover Base V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1999-2000 Land Rover Range Rover Base V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1999 Land Rover Range Rover Callaway V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1989-1990 Land Rover Range Rover County V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1992 Land Rover Range Rover County V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1993-1994 Land Rover Range Rover County V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2000 Land Rover Range Rover County V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1995 Land Rover Range Rover County Classic V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1993-1995 Land Rover Range Rover County LWB V8.4200cc Engine Components::Head Stud \u0026amp; Bolt Kits 1991 Land Rover Range Rover County SE V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1991 Land Rover Range Rover Great Divide V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1996-2002 Land Rover Range Rover HSE V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 2000 Land Rover Range Rover HSK V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1989 Land Rover Range Rover Hunter V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1991 Land Rover Range Rover Hunter V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1997 Land Rover Range Rover Kensington V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1992 Land Rover Range Rover LSE V8.3947cc Engine Components::Head Stud \u0026amp; Bolt Kits 1999 Land Rover Range Rover S V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 1995-2000 Land Rover Range Rover SE V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2001 Land Rover Range Rover SE V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 1993 Land Rover Range Rover Sport V8.3950cc Engine Components::Head Stud \u0026amp; Bolt Kits 2006-2009 Land Rover Range Rover Supercharged V8.4196cc Engine Components::Head Stud \u0026amp; Bolt Kits 1997 Land Rover Range Rover Vitesse V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 2000 Land Rover Range Rover Vitesse V8.4554cc Engine Components::Head Stud \u0026amp; Bolt Kits 2008 Land Rover Range Rover Sport LE V8.4196cc Engine Components::Head Stud \u0026amp; Bolt Kits 2006-2009 Land Rover Range Rover Sport Supercharged V8.4196cc Engine Components::Head Stud \u0026amp; Bolt Kits ","brand":"ARP","offers":[{"title":"Default Title","offer_id":42579583566079,"sku":"","price":191.41,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0630\/1106\/2015\/products\/group-052471fc-0217-4479-befe-00a28ba6feae-800__37639.jpg?v=1647875858","url":"https:\/\/aristocrat-autosport-llc.myshopify.com\/products\/arp-rover-3-9l-4-6l-v8-with-10-bolt-heads-head-stud-kit-arp157-4301","provider":"Aristocrat Autosport ","version":"1.0","type":"link"}