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SKU: 156-5201 | UPC: 672036037727
ARP Main Stud Kit for Ford 289/302/351W Early Cast Iron Block M8 Side Bolts
ARP 156-5201 main stud kit secures main caps in Ford 289 302 and 351W engines with early cast iron blocks and M8 side bolts found in vehicles from 1962 to 1995. This kit delivers consistent clamping force to handle high horsepower builds in classic Mustangs trucks and vans. It stops main cap walk eliminates fretting and shields block threads from damage for long-term engine reliability.
Key Features
- 8740 Chrome Moly Steel: In-house heat-treated to 190,000 PSI tensile strength for unmatched holding power under extreme loads.
- Rolled J-Form Threads: Formed after heat treatment creating threads 2000% stronger than cut threads for superior fatigue resistance.
- Complete Hardware Set: Includes hardened parallel-ground washers and heavy-duty nuts for precise even load distribution.
- Cap Walk Prevention: Locks main caps in place during high-rpm operation and boosted applications preventing misalignment.
- Block Thread Protection: Stud design reduces galling and stripping risks for easier installs and rebuilds.
Product Notes
- Verify engine block has M8 x 1.25 side bolts typical on pre-1970 Windsor cast iron blocks.
- Black oxide finish resists corrosion in harsh engine environments.
- Made in USA with meticulous quality checks for every component.
Installation Notes
- Professional installation recommended.
- Chase block threads with ARP tap set and use ARP moly lube on studs.
- Torque mains to 85-110 ft-lbs in sequence per ARP instructions included.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 1962-1971 | Ford | Fairlane | Early Cast Iron Block M8 Side Bolts |
| 1964-1973 | Ford | Mustang | Early Cast Iron Block M8 Side Bolts |
| 1966-1970 | Ford | Falcon | Early Cast Iron Block M8 Side Bolts |
| 1966-1977 | Ford | Bronco | Early Cast Iron Block M8 Side Bolts |
| 1967-1983 | Ford | F-100 | Early Cast Iron Block M8 Side Bolts |
| 1967-1983 | Ford | F-150 | Early Cast Iron Block M8 Side Bolts |
| 1968-1982 | Ford | Econoline | Early Cast Iron Block M8 Side Bolts |
| 1968-1976 | Ford | Torino | Early Cast Iron Block M8 Side Bolts |
| 1969-1979 | Ford | Ranchero | Early Cast Iron Block M8 Side Bolts |
Why Choose ARP?
- Trusted by racers since 1968 in demanding motorsports environments.
- Custom heat treatment process ensures every stud meets exact strength specs.
- Precision rolled threads and fit deliver repeatable results in performance engines.
Frequently Asked Questions
-
Q: Which Ford engines require this M8 side bolt kit?
A: Designed for 289 302 and 351W early cast iron Windsor blocks with M8 x 1.25 side bolts usually pre-1970 production verify by measuring your block. -
Q: What makes ARP studs stronger than OEM bolts?
A: 8740 chromoly construction with post-heat-treat rolled threads achieves 190,000 PSI strength far exceeding factory fasteners. -
Q: What torque specs apply and is warranty included?
A: Follow printed instructions typically 85-110 ft-lbs with ARP lube backed by ARP limited lifetime warranty against defects.
Shipping & Handling
- Method: UPS Ground
- Availability: In stock - ships same or next business day
- Packaging: Protective box 1 x 6 x 7 inches
- Weight: 2.1 lbs
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