B58 ARP 625+ Custom Age Main Stud Kit

Toyota BMW B58 625+ Custom Age Main Stud Kit

When we started developing our B58 Billet Main Cap system, we needed a main stud strong enough to handle the extreme loads of high-horsepower B58 builds. Working with ARP, we developed a 625+ Custom Age Main Stud Kit to provide the increased strength and clamping force needed for serious B58 performance applications.

Manufactured from ARP 625+ Custom Age material, these high-strength main studs provide exceptional tensile strength, fatigue resistance, and consistent clamping force for extreme-power applications.

This ARP Main Stud Kit is designed to replace BMW part numbers 11128644674 and 11127613127 for B58, B58A, B58C, and B58D engines found across various BMW chassis, including F22, F23, F30, F31, F32, F33, F34, F36, G20, G22, G23, G26, G30, G01, G02, G29, G42, and G43, as well as the Toyota GR Supra A90/A91.

Features & Benefits

• ARP 625+ Custom Age material
• Increased strength and fatigue resistance
• More consistent main-cap clamping
• Helps minimize main-cap movement under extreme loads
• Improved crankshaft and main-bearing stability
• Ideal for high-RPM and high-horsepower B58 builds
• Direct replacement for OEM bolt part #11128644674 and #11127613127
• Works with OEM B58 engine blocks and factory main caps
• Designed for use with 5150 AutoSport B58 Billet Main Caps

When opting for main studs instead of factory bolts, it's important to note that the engine builder should mic the bores. Using studs may require a line hone to ensure proper fitment and alignment. A line hone is a machining process that can be used to resize and reshape the main bearing bores, ensuring that they are perfectly round and concentric. This is crucial for ensuring proper oil clearance and preventing premature bearing wear. By mic'ing the bores and performing a line hone if necessary, engine builders can ensure that the main studs are installed correctly and that the engine will perform reliably and at its best.