Dropping a Gen V LT engine into your full-size GM B-body? Speed Engineering's 1-7/8" LT swap longtube headers are built specifically for the 1971–1996 GM B-body platform — mandrel bent, TIG-welded, and CNC-machined for a precise fit across Chevrolet, Buick, Oldsmobile, Pontiac, and Cadillac B-body applications spanning over two decades. Compatible with 5.3L and 6.2L LT1 and LT4 engines. Dyno proven to deliver over 25 rear-wheel horsepower over stock manifolds.
Built from 304 natural stainless steel with a merge spike and standard graphite manifold gaskets included.
⚠️ Important Installation Notes:
- Gen V LT direct injection engine swaps only — these headers are NOT compatible with SBC or BBC engines
- Due to older vehicle frame clearance, headers fit very tight and require Speed Engineering LT spark plug wires
- 4L80E or older Turbo 350/400 transmission — bellhousing ears may need to be trimmed for proper clearance
- LT4 engines may require an oil cooler adapter or delete kit
Features:
- 1-7/8" Primary Tubes with Merge Spike — Full-diameter flow from cylinder head to collector for maximum exhaust scavenging
- 3" Collector — Optimized for strong low-to-mid RPM torque
- Mandrel Bent Tubing — Consistent tube diameter through every bend; no crimping, no restriction
- CNC Machined Flanges — Precision fit at the cylinder head for a leak-free seal
- 304 Natural Stainless Steel Construction — Corrosion resistant, heat tolerant, and built to last
- Longtube Header Design — Maximum scavenging efficiency vs. shorty or mid-length headers
- Standard Graphite Manifold Gaskets Included
- Dyno Proven — 25+ RWHP gain on LT applications
- Compatible with 5.3L, 6.2L, LT1, and LT4 Engines
- V8 LT Engines Only
Vehicle Applications:
Note: All applications listed are Gen V LT swap conversions. These headers are not compatible with the original factory engines in these vehicles.
1971–1976 GM B-Body
- 1971 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser — LT Swap
- 1972 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser — LT Swap
- 1973 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser — LT Swap
- 1974 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser — LT Swap
- 1975 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser — LT Swap
- 1976 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser — LT Swap
1977–1981 GM B-Body
- 1977 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Bonneville, Catalina — LT Swap
- 1978 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Bonneville, Catalina — LT Swap
- 1979 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Bonneville, Catalina — LT Swap
- 1980 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Bonneville, Catalina — LT Swap
- 1981 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Bonneville, Catalina — LT Swap
1982–1989 GM B-Body
- 1982 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1983 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1984 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1985 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1986 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1987 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1988 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
- 1989 GM B-Body (RWD) — Caprice, Impala, LeSabre, Delta 88, Estate Wagon, Custom Cruiser, Parisienne — LT Swap
1990–1992 GM B-Body
- 1990 GM B-Body (RWD) — Caprice, Impala, Estate Wagon, Custom Cruiser — LT Swap
- 1991 GM B-Body (RWD) — Caprice, Roadmaster, Roadmaster Estate Wagon, Custom Cruiser — LT Swap
- 1992 GM B-Body (RWD) — Caprice, Roadmaster, Roadmaster Estate Wagon, Custom Cruiser — LT Swap
1993–1996 GM B-Body
- 1993 GM B-Body (RWD) — Caprice, Roadmaster, Roadmaster Estate Wagon, Fleetwood — LT Swap
- 1994 GM B-Body (RWD) — Caprice, Impala SS, Roadmaster, Roadmaster Estate Wagon, Fleetwood — LT Swap
- 1995 GM B-Body (RWD) — Caprice, Impala SS, Roadmaster, Roadmaster Estate Wagon, Fleetwood — LT Swap
- 1996 GM B-Body (RWD) — Caprice, Impala SS, Roadmaster, Roadmaster Estate Wagon, Fleetwood — LT Swap
Frequently Asked Questions:
Q: Will these headers work with my SBC or BBC engine? No. These headers are designed for Gen V LT direct injection engine swaps only and are not compatible with standard small block Chevy or big block Chevy engines.
Q: Do I need special spark plug wires? Yes. Due to tight frame clearance on older B-body platforms, Speed Engineering LT spark plug wires are required for proper fitment with these headers.
Q: Will these work with my LT4 engine? Yes, but the LT4 engine may require an oil cooler adapter or delete kit for proper fitment with these headers.
Q: Will these fit with a 4L80E or older Turbo 350/400 transmission? These headers may require trimming of the bellhousing ears on 4L80E or older Turbo 350/400 transmissions for proper clearance.
Q: What GM B-body models are compatible with these headers? These headers are compatible with a wide range of 1971–1996 GM B-body models including Chevrolet Caprice and Impala, Buick LeSabre, Roadmaster and Estate Wagon, Oldsmobile Delta 88 and Custom Cruiser, Pontiac Bonneville, Catalina and Parisienne, and Cadillac Fleetwood. Refer to the full vehicle applications list for year-by-year model details.
Q: What engines are these headers compatible with? These headers are compatible with GM Gen V LT V8 engines including 5.3L, 6.2L, LT1, and LT4.
Q: How much horsepower do these headers add? Speed Engineering's 1-7/8" LT swap longtube headers are dyno proven to add over 25 rear-wheel horsepower compared to stock exhaust manifolds on LT applications.
Q: What material are these headers made from? 304 natural stainless steel with full TIG-welded construction, CNC-machined flanges, and a merge spike.
Q: Are gaskets included? Yes. Standard graphite manifold gaskets are included with the headers.
Q: Are these headers street legal? No. These are race-only headers intended for closed-course competition use only. Installation on a street-driven vehicle may violate the Clean Air Act (42 U.S.C. 7522(a)(3)).
⚠️ Race Use Only: This product is manufactured and sold for installation on vehicles used solely for competition. Once installed, the vehicle may not be used, registered, or licensed for use on a public road or highway. Installation on a street-driven vehicle may violate the Clean Air Act 203(a)(3), 42 U.S.C. 7522(a)(3).
