{"product_id":"boss-hog-night-stalker-towing-torque-converter-gm-6l80e-6l90e-ls-lockup-4540hd","title":"Boss Hog Night Stalker Towing Torque Converter | GM 6L80E\/6L90E LS Lock-Up +200 Stall | 4540HD","description":"\u003cp\u003eThe Boss Hog 4540HD is a Night Stalker series lock-up towing torque converter for the GM 6L80E and 6L90E automatic transmissions behind LS engines, on the two-step input shaft. It adds roughly 200 to 300 RPM of stall over stock and is one of the lightest weight converters on the market, built to strengthen the factory weak points with new Torrington-style encased bearings and an oversized extreme-duty lock-up. It uses a factory 12.5 in core, a 12.125 in bolt circle, a 36-spline input shaft, a 36-spline modified heavy-duty stator, a hardened chrome moly impeller hub, and a factory 1.703 in crank pilot. Every unit is leak and pressure tested, digitally balanced, and made in the USA.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSeries: Night Stalker (Towing \/ HD)\u003c\/li\u003e\n\u003cli\u003eTransmission: GM 6L80E, 6L90E (LS, lock-up)\u003c\/li\u003e\n\u003cli\u003eStall Speed: 200-300 RPM over stock\u003c\/li\u003e\n\u003cli\u003eCore: 12.5 in (factory)\u003c\/li\u003e\n\u003cli\u003eBolt Circle: 12.125 in\u003c\/li\u003e\n\u003cli\u003eInput Spline: 36\u003c\/li\u003e\n\u003cli\u003eStator: 36-spline modified heavy duty\u003c\/li\u003e\n\u003cli\u003eLock-Up: Oversized extreme-duty\u003c\/li\u003e\n\u003cli\u003eImpeller Hub: Hardened chrome moly\u003c\/li\u003e\n\u003cli\u003eBearings: Torrington-style encased\u003c\/li\u003e\n\u003cli\u003eCrank Pilot: 1.703 in (factory)\u003c\/li\u003e\n\u003cli\u003eBolt Size: 10mm x 1.5 (Class 10+)\u003c\/li\u003e\n\u003cli\u003eAnti-Balloon Plates: No\u003c\/li\u003e\n\u003cli\u003eBalance: Digitally balanced\u003c\/li\u003e\n\u003cli\u003eTowing Note: Needs transmission cooler to exceed 30,000 GVW\u003c\/li\u003e\n\u003cli\u003eBuild: Leak \u0026amp; pressure tested; made in USA\u003c\/li\u003e\n\u003cli\u003ePart Number: 4540HD\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWARNING: 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.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003ch5\u003eWhat transmission does the Boss Hog 4540HD fit?\u003c\/h5\u003e\n\u003cp\u003eIt fits the GM 6L80E and 6L90E lock-up transmissions behind LS engines, on the two-step input shaft.\u003c\/p\u003e\n\u003ch5\u003eHow much stall does it add?\u003c\/h5\u003e\n\u003cp\u003eThe 4540HD adds roughly 200 to 300 RPM over the stock stall. Advertised stall varies with your vehicle setup.\u003c\/p\u003e\n\u003ch5\u003eIs this a lock-up converter?\u003c\/h5\u003e\n\u003cp\u003eYes. It uses an oversized extreme-duty lock-up.\u003c\/p\u003e\n\u003ch5\u003eIs it built for towing?\u003c\/h5\u003e\n\u003cp\u003eYes. It is a heavy-duty towing unit; use a transmission cooler to exceed 30,000 GVW.\u003c\/p\u003e\n\u003ch5\u003eWhat are the key fitment specs?\u003c\/h5\u003e\n\u003cp\u003eIt is a 36-spline input with a 12.125 in bolt circle, a 12.5 in factory core, and a 1.703 in crank pilot.\u003c\/p\u003e\n\u003ch5\u003eWhich Boss Hog series should I choose?\u003c\/h5\u003e\n\u003cp\u003eBoss 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.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What transmission does the Boss Hog 4540HD fit?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"It fits the GM 6L80E and 6L90E lock-up transmissions behind LS engines, on the two-step input shaft.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How much stall does it add?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The 4540HD adds roughly 200 to 300 RPM over the stock stall. Advertised stall varies with your vehicle setup.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this a lock-up converter?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. It uses an oversized extreme-duty lock-up.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is it built for towing?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. It is a heavy-duty towing unit; use a transmission cooler to exceed 30,000 GVW.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What are the key fitment specs?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"It is a 36-spline input with a 12.125 in bolt circle, a 12.5 in factory core, and a 1.703 in crank pilot.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Which Boss Hog series should I choose?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"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.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"ACC Performance Products","offers":[{"title":"Default Title","offer_id":42927643230256,"sku":"BKCP_4540HD","price":553.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0586\/9548\/3440\/files\/ATC4540HD.jpg?v=1775914477","url":"https:\/\/berryperformancesales.com\/products\/boss-hog-night-stalker-towing-torque-converter-gm-6l80e-6l90e-ls-lockup-4540hd","provider":"Berry Performance Sales","version":"1.0","type":"link"}