Description: PRODUCT DESCRIPTION ARP 155-4201 6-Cylinder Head Stud Kit (12-Point Nuts)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 “aircraftâ€Â� 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 “stretchâ€Â� 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 they are the best on the market today and the favorite of leading professional engine builders in all forms of racing. HEAD STUDS vs. BOLTS...A TECHNICAL DISCUSSION ARP’s factory Tech Representatives are often asked which is better cylinder head studs or bolts. The answer invariably depends on the installation. 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 “twistedâ€Â� 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 “relaxedâ€Â� 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.*NOTE : IMAGE SHOWN MAY NOT BE ACTUAL PRODUCT PLEASE CALL FOR DETAILS*** THIS PRODUCT FITS THE FOLLOWINGMakeModelYearEngine TypeApplication NoteDetailColorFord(N/A)(N/A)Big Block 390-428FE series with factory heads or Edelbrock heads(N/A)(N/A) Back to topABOUT THE MANUFACTURER About ARP History & Background on ARP They say that to be successful you must identify a need and satisfy it. Back in 1968 racing enthusiast Gary Holzapfel saw that many of his friends’ broken engines were caused by fastener failure. At the time there were no commercially available studs and bolts up to the challenge. So Holzapfel called upon his many years of fastener making experience for a leading aerospace subcontractor and founded ARP® (Automotive Racing Products). In the ensuing years the firm has grown from what was literally a backyard garage workshop into a highly diversified manufacturer with five operational entities in Southern California with a combined area in excess of 200 000 square feet. These include forging machining finishing and packaging/warehousing facilities in Santa Paula and Ventura California. There is even a unique racing-themed restaurant at the main Santa Paula facility - called “Hozy’s Grill” - which is open to the public. Today ARP’s product line contains thousands of part numbers and has expanded to include virtually every fastener found in an engine and driveline. These range from quality high performance replacement parts to exotic specialty hardware for Formula 1 IndyCar NASCAR and NHRA drag racing and marine applications. Back to topABOUT AMCO AUTO PARTS, LLC Since 2002 AMCO Auto Parts, LLC has been striving to supply and support car enthusiasts around the world with the products and service they deserve. With the economy the way it is we understand how important pricing is. Here at AMCO Auto Parts, LLC our car parts are some of the lowest prices around. With that in mind you will not lose quality. We offer auto car and truck parts from nearly 150 manufacturers. These companies are some of the most highly regarded in the automotive industry today. Our highly skilled staff is ready to answer any of your questions. Our hours of operation are Monday through Thursday 9am to 5:30pm and Friday from 9am to 4pm. Should you have any question, please message us! We would like to thank our new and existing customers for their trust and support in our company. AMCO Auto Parts, LLC will continue to provide top notch customer service along with quality car parts and low pricing. Back to top PLEASE BE ADVISED* Please note that products may be shipping from warehouses located outside of New Jersey. If your shipment is time sensitive please contact us to confirm your items warehouse location. * If your shipping price varies from the standard shipping cost we have listed we will notify you immediately for additional shipping charges or give you the option to cancel your order and receive a full refund. * Please note for international orders it may take up to five business days for your item to be ready for shipment. * International Orders may take from 10-40 days for delivery depending on item purchased customs may take longer to inspect certain items.Size Brand and Location of an item is being shipped to also matters. * Product images may not be vehicle specific. Please contact us for more details before ordering.Back to topCONTACT US Feedback:I strive for 100% positive feedback and a 5 star Detailed Seller Rating. If you feel I do not deserve that then please contact me as I try to make sure every customer is 100% satisfied. I am very accommodating please contact me for any special requests or for any questionsAMCO AUTO PARTS, LLC
Price: 207.13 USD
Location: Paterson, New Jersey
End Time: 2025-01-15T22:25:45.000Z
Shipping Cost: 8.99 USD
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Item Specifics
Restocking Fee: No
Return shipping will be paid by: Buyer
Returns Accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
Brand: ARP
Manufacturer Part Number: 155-4201
