SKU: 201-4305 | UPC: 672036042776
ARP BMW E30 M20 2.5L 6cyl Head Stud Kit 1987-1991 325i 325is 325iX
ARP head stud kit 201-4305 fits 1987-1991 BMW E30 models with M20 2.5L engines including 325i 325is and 325iX. These studs provide consistent clamping force to seal cylinder heads under high boost or compression. Built for reliability in street and track use with precision engineering.
Key Features
- ARP 8740 Chromoly Steel: Heat-treated to 200000 PSI tensile strength for dependable head gasket sealing
- Stud Design: Minimizes main cap and block thread damage while ensuring accurate torque values
- Rolled Threads: Offer 1000% greater fatigue strength than cut threads for repeated torquing
- Matched Hardware: Includes washers and instructions for direct bolt-in replacement
- Multi-Purpose Fit: Handles daily driving track days and drag strip demands without failure
Product Notes
- Inspect head and block surfaces before installation for flatness
- Torque to ARP specs after engine warm-up cycles
- Compact packaging fits easily in tool bags for trackside service
Installation Notes
- Professional installation recommended.
- Apply ARP Ultra-Torque fastener lubricant on threads and under washer faces
- Torque in ARP-specified sequence starting at center studs
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 1987-1991 | BMW | 325i | Base |
| 1987-1991 | BMW | 325is | Base |
| 1988-1991 | BMW | 325iX | Base |
Why Choose ARP?
- Decades of motorsport victories prove real-world strength
- Exact-fit kits eliminate guesswork in high-horsepower setups
- Engineered threads resist galling and maintain clamp over time
Frequently Asked Questions
-
Q: Does this kit fit all E30 M20B25 engines?
A: Yes it matches 1987-1991 BMW 325i Base 325is Base and 325iX Base with M20 2.5L six-cylinder -
Q: What material are the studs made from?
A: High-grade 8740 chromoly steel heat-treated to 200000 PSI with rolled threads for maximum fatigue resistance -
Q: What is the ARP warranty?
A: Lifetime warranty against manufacturing defects when installed and torqued per ARP guidelines
Shipping & Handling
- Method: UPS Ground or USPS Priority
- Availability: In stock - ships same or next business day
- Packaging: Secure foam-lined box 12 x 7 x 1.5 inches
- Weight: 2.1 lbs
ARP
ARP (Automotive Racing Products) is the world’s premier manufacturer of high-strength engine and driveline fasteners—head studs and bolts, main studs, rod bolts, and more—engineered and manufactured in-house from start to finish for race-proven reliability. With vertically integrated processes that include cold heading, machining, heat-treating, thread rolling after heat treat, and rigorous QA, ARP maintains aerospace-level certifications (ISO 9001 and AS9100) and validates every part for repeatable clamp load and fatigue resistance. Signature alloys such as 8740 chromoly, ARP2000, L19, and Custom Age 625+ deliver ultimate tensile strengths up to the super-alloy range, while ARP Ultra-Torque fastener assembly lubricant helps achieve consistent pre-load during installation. From street performance builds to professional motorsport programs, ARP fasteners provide precise fitment, superior metallurgy, and the durability needed to keep engines together at elevated cylinder pressures and...
View ARP Products
ARP Head Studs
ARP head studs replace factory head bolts with precision-machined threaded studs that provide more consistent and repeatable clamping force on the cylinder head gasket. Unlike head bolts that apply torque through both rotational and tensile forces, head studs allow the nut to be torqued concentrically on a stud that is already stationary, producing more even clamping load across the entire head gasket surface. Popular ARP Head Stud Applications ARP head studs are available for a wide range of performance and turbocharged engines including the Subaru EJ series, Honda K series and B series, Mitsubishi 4G63 and 4B11, Honda Civic and Integra, Toyota 2JZ-GTE, Nissan SR20DET and RB series, GM LS series, Ford Coyote and 5.0, and Dodge/Chrysler HEMI applications. ARP offers both 8740 chromoly and ARP2000 alloy head stud kits, with the ARP2000 material providing approximately 20 percent higher tensile strength for high-boost applications above 30 psi. Why are head studs preferred over head b...
View ARP Head Studs Products
Head Components
This collection covers cylinder head components including head gaskets, head studs, and complete head assemblies for performance engine builds and high-output applications, serving vehicle owners and builders who need reliable components for maintenance, restoration, or performance enhancement. Arp head studs, cometic head gaskets, and edelbrock or afr cylinder heads are foundational brands in performance cylinder head work, providing buyers with the confidence that comes from sourcing from recognized suppliers with documented fitment data. Proper head bolt torque sequence and head gasket compression thickness selection directly affect combustion sealing integrity and engine longevity, and selecting the correct specification for the specific application is the most important step before any installation. Whether the goal is restoring OEM function, addressing a worn component, or improving beyond factory performance, this collection addresses each need with confirmed-fit parts. Popul...
View Head Components Products
Head Stud & Bolt Kits
This collection covers cylinder head components including head gaskets, head studs, and complete head assemblies for performance engine builds and high-output applications, serving vehicle owners and builders who need reliable components for maintenance, restoration, or performance enhancement. Arp head studs, cometic head gaskets, and edelbrock or afr cylinder heads are foundational brands in performance cylinder head work, providing buyers with the confidence that comes from sourcing from recognized suppliers with documented fitment data. Proper head bolt torque sequence and head gasket compression thickness selection directly affect combustion sealing integrity and engine longevity, and selecting the correct specification for the specific application is the most important step before any installation. Whether the goal is restoring OEM function, addressing a worn component, or improving beyond factory performance, this collection addresses each need with confirmed-fit parts. Popul...
View Head Stud & Bolt Kits Products


