Swapping a GM LS engine into your Fox Body or SN95 Mustang and want everything you need to do it right? This combo kit pairs Speed Engineering's 1-7/8" LS swap longtube headers with a complete AJE K-member package — giving you the headers, K-member, motor mounts, spring perches, and steering shaft all in one purchase. Dyno proven to deliver over 25 rear-wheel horsepower over stock manifolds.
Built from 304 natural stainless steel with merge spikes and standard graphite manifold gaskets included.
⚠️ Important Installation Notes:
- GM LS engine swaps only — these headers are NOT designed for Ford engines of any kind
- Headers have only been tested successfully with AJE Motor Mounts, Flaming River Steering Shafts, and AJE K-Members — compatibility with other combinations is unknown and not guaranteed
Speed Engineering Headers — Kit Includes:
- 1-7/8" Longtube Headers with Merge Spikes
- Standard Graphite Manifold Gaskets
AJE Suspension — Kit Includes:
- 1979–2004 AJE K-Member
- LS Engine Motor Mounts
- 1979–2004 Spring Perches — Allows use of factory A-arms and springs
- 1979–2004 Manual or Power Steering Shaft Kit
Header Features:
- Full 1-7/8" Primary Tubes with Merge Spikes — Full-diameter flow from cylinder head to collector for maximum exhaust scavenging
- 3" Collector with Merge Spikes — Optimized merge geometry 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 LS applications
- Compatible with 4.8L, 5.3L, 6.0L, 6.2L, LS1, LS2, LS3, LS6, and LSA Engines
- V8 LS Engines Only
Vehicle Applications:
Note: All applications listed are GM LS engine swap conversions. These headers are not compatible with Ford engines of any kind.
Ford Mustang — Fox Body (RWD)
- 1979 Ford Mustang (RWD) — LS Swap
- 1980 Ford Mustang (RWD) — LS Swap
- 1981 Ford Mustang (RWD) — LS Swap
- 1982 Ford Mustang (RWD) — LS Swap
- 1983 Ford Mustang (RWD) — LS Swap
- 1984 Ford Mustang (RWD) — LS Swap
- 1985 Ford Mustang (RWD) — LS Swap
- 1986 Ford Mustang (RWD) — LS Swap
- 1987 Ford Mustang (RWD) — LS Swap
- 1988 Ford Mustang (RWD) — LS Swap
- 1989 Ford Mustang (RWD) — LS Swap
- 1990 Ford Mustang (RWD) — LS Swap
- 1991 Ford Mustang (RWD) — LS Swap
- 1992 Ford Mustang (RWD) — LS Swap
- 1993 Ford Mustang (RWD) — LS Swap
Ford Mustang — SN95 (RWD)
- 1994 Ford Mustang (RWD) — LS Swap
- 1995 Ford Mustang (RWD) — LS Swap
- 1996 Ford Mustang (RWD) — LS Swap
- 1997 Ford Mustang (RWD) — LS Swap
- 1998 Ford Mustang (RWD) — LS Swap
- 1999 Ford Mustang (RWD) — LS Swap
- 2000 Ford Mustang (RWD) — LS Swap
- 2001 Ford Mustang (RWD) — LS Swap
- 2002 Ford Mustang (RWD) — LS Swap
- 2003 Ford Mustang (RWD) — LS Swap
- 2004 Ford Mustang (RWD) — LS Swap
FAQ
What is included in this kit?
This kit includes Speed Engineering 1-7/8" LS swap longtube headers with merge spikes and graphite manifold gaskets, plus the AJE K-member, LS engine motor mounts, 1979–2004 spring perches, and a manual or power steering shaft kit.
Will these headers work with my Ford engine?
No. These headers are designed for GM LS engine swaps only and are not compatible with Ford engines of any kind.
What motor mounts and K-member are compatible with these headers?
These headers have only been tested successfully with AJE Motor Mounts, Flaming River Steering Shafts, and AJE K-Members — all of which are included in this kit. Compatibility with other combinations is unknown and not guaranteed.
Will the AJE spring perches allow me to keep my factory A-arms and springs?
Yes. The included 1979–2004 spring perches are designed to allow the use of factory A-arms and springs.
What is the difference between this listing and the headers-only version?
This listing is a complete combo kit that includes the AJE K-member, motor mounts, spring perches, and steering shaft kit in addition to the Speed Engineering headers. The headers-only listing includes just the headers and gaskets.
What LS engines are these headers compatible with?
These headers are compatible with GM LS V8 engines including 4.8L, 5.3L, 6.0L, 6.2L, LS1, LS2, LS3, LS6, and LSA.
How much horsepower do these headers add?
Speed Engineering's 1-7/8" LS swap longtube headers are dyno proven to add over 25 rear-wheel horsepower compared to stock exhaust manifolds on LS applications.
What material are these headers made from?
304 natural stainless steel with full TIG-welded construction, CNC-machined flanges, and merge spikes.
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).
