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SKU: 206-5401 | UPC: 672036008017
ARP Pro Series Main Stud Kit for BMC A-Series Engines 1958-1980 Mini Cooper Sprite Midget
The ARP 206-5401 main stud kit upgrades crankshaft retention in all BMC A-Series engines including 948cc 997cc 1098cc 1275cc and 1293cc variants found in Mini Cooper Austin Healey Sprite MG Midget and Morris Minor. These 8740 chrome-moly studs deliver 190,000 psi tensile strength with black oxide finish for precise clamping force and alignment under high-RPM street race and rally loads. Precision-ground and heat-treated with rolled threads this kit replaces factory bolts directly without block modifications.
Key Features
- 8740 Chrome-Moly Construction: 190,000 psi tensile strength holds crankshaft securely during extreme high-RPM operation
- Black Oxide Finish: Rolled threads after heat treatment resist fatigue and protect against corrosion
- Included Hardware: Parallel-ground washers and 12-point nuts distribute load evenly across all five main caps
- Bolt-In Fitment: Direct replacement for factory main bolts in stock or modified A-Series blocks
- Complete Kit: 10 studs 10 washers and 10 nuts cover full engine installation needs
Product Notes
- Fits all BMC A-Series engines 948cc to 1293cc
- Torque to 65 ft-lbs with ARP Ultra-Torque lube
- Ships in protective retail box
Installation Notes
- Professional installation recommended.
- Use ARP Ultra-Torque lube on threads and under nut faces.
- Torque in 3 steps to 65 ft-lbs check main bearing clearance after install.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 1958-1971 | Austin Healey | Sprite | MKI MKII MKIII MKIV |
| 1961-1979 | MG | Midget | MKI MKII MKIII |
| 1959-2000 | Mini | Cooper | A-Series All |
| 1959-1980 | Morris | Mini | A-Series All |
| 1963-1971 | Morris | Minor | 1000 Series |
Why Choose ARP?
- Over 60 years of championship-winning fastener engineering
- Trusted by every major race series worldwide
- Limited lifetime warranty
Frequently Asked Questions
-
Q: Fits 1275cc Cooper S?
A: Yes fits all BMC A-Series engines 948cc to 1293cc including Cooper S -
Q: Material and torque spec?
A: 8740 chrome-moly studs torque to 65 ft-lbs with ARP Ultra-Torque lube -
Q: Reusable after install?
A: Yes if undamaged and threads measure within ARP specifications
Shipping & Handling
- Method: UPS or FedEx Ground
- Availability: In stock - ships same or next business day
- Packaging: Protective retail box 8 x 6 x 1.5 inches
- Weight: 1 lb
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