Upgrading the exhaust on your classic B-body Impala or Caprice with a small block Chevy? Speed Engineering's 1-5/8" SBC longtube headers are a direct-fit upgrade for 1971–1993 B-body applications — mandrel bent, TIG-welded, and CNC-machined with oval ports, a 3" collector with merge spike, and zinc header bolts included. Built from 304 natural stainless steel with standard graphite manifold gaskets included. Dyno proven.
⚠️ Important: These headers will NOT work on LT1 engines. Compatible with SBC 305 and 350 V8 engines only.
Features:
- 1-5/8" Primary Tubes with Merge Spike — Sized for improved flow on SBC 305 and 350 applications
- 1-3/4" x 1-1/2" Oval Ports — Matches standard SBC oval port cylinder head configurations
- 3" Collector with Merge Spike — Optimized merge geometry for strong low-to-mid RPM torque
- Longtube Header Design — Maximum scavenging efficiency vs. shorty or mid-length headers
- Mandrel Bent Tubing — Consistent tube diameter throughout; no crimping, no restriction
- CNC Machined Flanges — Precision fit at the cylinder head for a leak-free seal
- 17-3/8" Center to Center Outer Bolt Holes — Standard SBC bolt spacing for direct fitment verification
- 304 Natural Stainless Steel Construction — Corrosion resistant, heat tolerant, and built to last
- Standard Graphite Manifold Gaskets Included
- 10x1.5x25 Zinc Header Bolts Included
- Compatible with SBC 5.0L/305 and 5.7L/350 V8 Engines
- V8 Engines Only
Vehicle Applications:
Note: Will NOT work on LT1 engines. SBC 305/350 only.
Chevrolet Impala — B-Body (RWD)
- 1971 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1972 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1973 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1974 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1975 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1976 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1977 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1978 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1979 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1980 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1981 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1982 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1983 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1984 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1985 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1986 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1987 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1988 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1989 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1990 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1991 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1992 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
- 1993 Chevrolet Impala (RWD) — SBC 5.0L/5.7L
Chevrolet Caprice — B-Body (RWD)
- 1971 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1972 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1973 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1974 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1975 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1976 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1977 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1978 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1979 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1980 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1981 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1982 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1983 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1984 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1985 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1986 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1987 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1988 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1989 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1990 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1991 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1992 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
- 1993 Chevrolet Caprice (RWD) — SBC 5.0L/5.7L
Frequently Asked Questions:
Q: Will these headers work on an LT1 engine? No. These headers are designed for small block Chevy 305 and 350 V8 engines only and will not work on LT1 engines. The Caprice transitioned to the LT1 engine in 1994 — this header covers 1971–1993 SBC applications only.
Q: What is the difference between these longtube headers and the SBC mid-length B-body headers in the SBC universal mid-length kit (25-1230)? Part 25-1231 is a longtube header specifically designed for the 1971–1993 B-body Impala and Caprice — offering maximum exhaust scavenging with a longer primary tube for peak performance. The SBC mid-length universal headers (25-1230) cover a wider range of platforms including F-body, A-body, X-body, G-body, and B-body but use a shorter mid-length design. Choose longtubes for maximum performance, mid-length for a balance of performance and fitment flexibility.
Q: What port shape do these headers use? These headers use 1-3/4" x 1-1/2" oval ports, compatible with standard SBC oval port cylinder head configurations.
Q: What is the bolt hole spacing on these headers? The outer bolt holes are 17-3/8" center to center, matching standard SBC head bolt spacing.
Q: What bolts are included? 10x1.5x25 zinc header bolts are included with the headers.
Q: What collector size do these headers use? These headers feature a 3" collector with merge spike.
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).