The Boss Hog 49451 is a Night Stalker series lock-up torque converter for the GM 4L60E, 4L65E, and 4L70E (300mm) automatic transmissions behind LS engines, on the 30-spline two-step input shaft used from 1998 up. It runs a 1,600 to 2,200 RPM stall, close to stock, for a mild street feel. It strengthens the factory weak points with a much thicker, stronger lock-up liner, a modified heavy-duty stator, and new Torrington-style encased bearings so it handles more power and runs cooler. It uses the factory 12 in core, an 11.063 in bolt circle, and a factory 1.703 in crank pilot. Every unit is leak and pressure tested, digitally balanced, and made in the USA.
- Series: Night Stalker
- Transmission: GM 4L60E, 4L65E, 4L70E (300mm, LS, lock-up)
- Application: LS engines, 1998-up 2-step input shaft
- Stall Speed: 1,600-2,200 RPM
- Core: 12 in (factory)
- Bolt Circle: 11.063 in (factory)
- Input Spline: 30
- Lock-Up: Yes (extreme-duty)
- Impeller Hub: Hardened chrome moly
- Bearings: Torrington-style encased
- Stator: Modified heavy duty
- Crank Pilot: 1.703 in (factory)
- Bolt Size: 10mm x 1.5 (Class 10)
- Anti-Balloon Plates: No
- Balance: Digitally balanced
- Build: Leak & pressure tested; made in USA
- Part Number: 49451
WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
FAQ
What transmission does the Boss Hog 49451 fit?
It fits the GM 4L60E, 4L65E, and 4L70E (300mm) lock-up transmissions behind LS engines, on the 30-spline two-step input shaft used from 1998 up.
What is the stall speed?
The 49451 has a 1,600 to 2,200 RPM stall, close to stock. Advertised stall varies with your vehicle setup.
Is this a lock-up converter?
Yes. It uses an extreme-duty lock-up with a thicker, stronger liner than the factory converter.
What are the key fitment specs?
It is a 30-spline input with an 11.063 in bolt circle, a 12 in factory core, and a 1.703 in crank pilot.
Which Boss Hog series should I choose?
Boss Hog groups these converters by build level. Night Stalker suits stock to mild combinations, Street Bandit is the step up once you have upgraded two or more items such as intake, heads, headers, exhaust, cam, or gearing, and the Out Law racing series is for power adders like nitrous, a supercharger, a turbocharger, or a trans brake.
