ARP Pro Series torque converter bolt kit for GM 4L60/4L80 — 6-piece chromoly, 12-point head, black oxide

ARP 2307305 is a six-piece Pro Series torque converter bolt kit engineered for 4L60 and 4L80 transmissions, offering chromoly strength, a 12-point head and black oxide finish for durable clamping reliability.

This bolt kit supplies the exact hardware you need to secure a torque converter to the flexplate on GM 4L60/4L80 applications. Each bolt measures 10 mm x 1.50 thread with a length of 0.590 inches and features a high-strength chromoly construction with a black oxide coating for corrosion resistance and consistent torque signatures. The 12-point head improves socket engagement, while the kit’s vehicle-specific fitment reduces guesswork during installation.

What makes these bolts stronger than the OEM fasteners?

ARP uses a chromoly alloy and controlled manufacturing to increase shear and tensile strength over typical stamped or mild-steel factory bolts. That higher material strength helps resist stretching and failure under repeated clutch engagement and high-torque conditions.

• Chromoly construction for improved tensile and shear capacity
• Precision threads for consistent clamping force
• 12-point head for better socket contact and reduced rounding
• Black oxide finish for basic corrosion resistance

How do I know these fit my transmission?

This ARP kit is listed as part number 230-7305 and is specified for GM 4L60 and 4L80 transmission models. The kit’s 10 mm x 1.50 thread and 0.590 in length match the common factory thread engagement for those converters, making it a direct replacement in compatible setups.

• Part number: 2307305 (ARP Pro Series)
• Fits: 4L60 and 4L80 applications (vehicle-specific compatibility)
• Thread: 10 mm x 1.50; Length: 0.590 in
• Quantity: set of 6 bolts, suitable for most converter patterns

What installation benefits does the 12-point head provide?

The 12-point head increases contact surface with the socket, allowing tighter access in cramped areas and reducing the likelihood of rounding compared with worn 6-point fasteners. This design is useful when aligning the converter and reaching bolts near the transmission bellhousing.

• Easier access in tight bellhousing spaces
• Better torque application and reduced slippage
• Compatible with standard 12-point sockets for workshop tooling

Are there corrosion or longevity considerations?

ARP applies a black oxide layer that provides modest corrosion resistance and a smoother finish for assembly; however, black oxide is not a heavy-duty plating like zinc or cadmium. For prolonged exposure to harsh environments, consider additional anti-seize or protective coatings during installation.

• Black oxide finish reduces surface rust and improves appearance
• Chromoly core maintains mechanical strength over time
• Use thread lubricant or anti-seize per ARP guidance for best results

Who this is for: Technicians, engine builders and DIY enthusiasts replacing or upgrading torque converter fasteners on GM 4L60/4L80 transmissions will value the ARP 2307305 kit. Choose this set when you want a direct-fit, higher-strength alternative to OEM hardware for drivetrain reliability during rebuilds, high-torque builds or routine maintenance.

• Package weight: 0.5 pounds
• Fit type: Vehicle Specific
• Includes six 10 mm x 1.50, 0.590 in long, 12-point chromoly bolts