The Boss Hog 49451 Night Stalker Torque Converter is designed for GM LS-based vehicles equipped with 4L60E, 4L65E, or 4L70E transmissions (1998 and newer with 300mm input shaft). With a stall range of 1600–2200 RPM, this converter is ideal for near-stock applications, offering smooth engagement and enhanced drivability while maintaining the benefits of a lock-up design.

Built from a factory-size 12-inch core and tested to strict quality standards, this unit features a hardened chromoly impeller hub, heavy-duty stator, and encased Torrington bearings for long-lasting performance. Each converter is leak-tested, digitally balanced, and proudly made in the USA.

Upgrade Suggestions:
Choose the Street Bandit Series if your build includes aftermarket intake, cam, or exhaust. For setups using nitrous, turbos, superchargers, or a trans brake, opt for the Outlaw Series.

Key Features:

• Stall Speed Range: 1600–2200 RPM

• Transmission Compatibility: GM 4L60E / 4L65E / 4L70E (1998+ LS with 300mm input shaft)

• Lock-Up Compatible: Yes

• Core Diameter: 12 inches (factory size)

• Input Splines: 30

• Crank Pilot Diameter: 1.703 inches

• Bolt Circle Diameter: 11.125 inches

• Bolt Size: 10mm x 1.5 pitch (Class 10)

• Anti-Balloon Plate: Not included

• Construction Details:

  • Hardened chromoly impeller hub

  • Encased Torrington-style bearings

  • Modified heavy-duty stator

  • Extreme-duty lock-up liner

  • 4-corner tack welded or furnace brazed fins

• Tested: Leak and pressure tested, digitally balanced

• Material: Steel

• Finish: Black painted

• Made in the USA

• Quantity: Sold individually

Vehicle Fitment:

• GM LS-powered vehicles with 4L60E, 4L65E, or 4L70E automatic transmissions

• Fits 1998 and newer with 300mm 2-step input shaft

• Ideal for daily drivers and light-performance applications

What's Included:

• (1) Boss Hog 49451 Night Stalker Lock-Up Torque Converter

Installation Tips:

• Use Type F transmission fluid

• Always install an auxiliary transmission cooler

• Apply blue Loctite to all torque converter bolts