About ARPSince 1968 ARP have developed their own solutions to improve the reliability of racing engines. ARP is a brand known around the world as the leader in the field of reinforced engines parts : head studs and bolts rod ends and crankshaft bolts flywheel and pressure plate bolts... With almost 50 years of experience ARP offers a wide range of products to satisfy the needs of all motorists and tuners.Depending on use ARP offers a large choice of high grade material in the fabrication of their products. Here are the main materials used :ARP 8740 (Chromoly) : the material with the best quality for the Retail EUR inc VAT" offering excellent performances for the majority of “racing” applications. Thanks to different surface and thermal treatments applied by ARP during manufacturing this material benefits from a tensile strength typically rated at 200.000 psi.ARP 2000 : made from high grade steel alloy specifically optimized to offer improved resistance compared to the 8740 model for tensile strength up to 220.000 psi. The ARP 2000 is frequently recommended for engines used in intense disciplines such as circuit racing or drag racing.L19 : made from ""premium"" steel which has received numerous treatments offering a more substantial resistance compared to the ARP 2000 (260.000 psi tensile strength).The L19 is recommended for high powered engines used in intense disciplines such as circuit racing or drag racing. However unlike the ARP 2000 and 8740 the material which the L19 is made from is not rust proof and requires certain precautions for use.Custom Age : new alloy designed by ARP this material has outstanding resistant properties (up to 280.000 psi of tensile strength). Completely rust proof it is exclusive to ARP and is the best solution existing on the market.For more technical information don't hesitate to check out the ARP official site."