OPGI.com works best with JavaScript enabled.
Early Black Friday! Save up to 20% off Restoration! - use code: BIGDEAL20W
1‑800‑243‑8355
  • As seen on
  • Lokar Car Show Series
  • Mecum Auctions
Photo of Muffler, Flowmaster, 40 Series, 2-1/2
Illustrative Only

Flowmaster

Muffler, Flowmaster, 40 Series, 2-1/2", Offset Inlet/Outlet, 409S

Fits 1982–1986 Bonneville View fitment for 29 models
Part# FM80425
Mfg# 8042543
Sold As Each
$123.99
List Price: $136.95
You Save $12.96
Arriving Soon
Add To Wishlist 

The Original 40 series muffler delivers an aggressive exterior and interior tone. If you're looking for that original Flowmaster sound this is the muffler is for you. Constructed of 16 gauge 409S stainless steel and fully MIG welded for maximum durability.

Features: Durable fully welded 409SS stainless steel Aggressive Sound Exterior Exhaust Tone Noticeable interior resonance Excellent Street/Strip and Off Road application Body measures 13" x 9.75" and 4" tall Overall length is 19"

Notes

  • This item is not eligible for any further discounts or promotional pricing.
4
This product does not require an EO in California. By nature of its design, it is legal for sale and use in all 50 states. Replacement parts included. Learn More

Find Item In These Catalogs

  • 2024 Cadillac 1936-1993 142
  • 2024 Chevelle, El Camino 64-77 391
  • 2024 Cutlass, F-85 & 442 61-77 256
  • 2024 GM G-Body 1978-1988 211
  • 2024 Grand Prix 1962-77 223
  • 2024 GTO, LeMans & Tempest 284
  • 2024 Monte Carlo 70-77 244
  • 2024 Riviera 1963-76 124
  • 2024 Skylark, GS & GSX 61-72 227
WARNING: This product can expose you to chemicals including lead, sulfur, nickel, chromium, vanadium, titanium, polyvinyl chloride, and 4,4’-methylenebis (2-chloroaniline), 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.

Vehicle Fitment

Year Make Model Application Details
1982 Buick Grand National 40 Series - Offset/Offset - 2-1/2" in/out
1984–1987 Buick Grand National 40 Series - Offset/Offset - 2-1/2" in/out
1978–1987 Buick Regal 40 Series - Offset/Offset - 2-1/2" in/out
1963–1976 Buick Riviera 40 Series (Offset/Offset) - 2-1/2" in/out
1961–1972 Buick Skylark 40 Series (Offset/Offset) - 2-1/2" in/out
1983–1987 Buick T-Type 40 Series - Offset/Offset - 2-1/2" in/out
1938–1953 Cadillac 60 Special 40 Series - Offset/Offset - 2-1/2" in/out
1959–1993 Cadillac DeVille 40 Series - Offset/Offset - 2-1/2" in/out
1953–1993 Cadillac Eldorado 40 Series - Offset/Offset - 2-1/2" in/out
1954–1993 Cadillac Fleetwood 40 Series - Offset/Offset - 2-1/2" in/out
1939–1951 Cadillac Series 60 40 Series - Offset/Offset - 2-1/2" in/out
1939–1951 Cadillac Series 61 40 Series - Offset/Offset - 2-1/2" in/out
1940–1964 Cadillac Series 62 40 Series - Offset/Offset - 2-1/2" in/out
1939–1951 Cadillac Series 63 40 Series - Offset/Offset - 2-1/2" in/out
1940–1964 Cadillac Series 65 40 Series - Offset/Offset - 2-1/2" in/out
1936–1953 Cadillac Series 70 40 Series - Offset/Offset - 2-1/2" in/out
1976–2004 Cadillac Seville  
1964–1977 Chevrolet Chevelle 40 Series - offset/offset - 2-1/2" in/out
1960–1969 Chevrolet Corvair 40 Series - offset/offset - 2-1/2" in/out
1961–1965 Chevrolet Corvair FC 40 Series - offset/offset - 2-1/2" in/out
1964–1987 Chevrolet El Camino 1964–1977: 40 Series - offset/offset - 2-1/2" in/out
1978–1987: 40 Series - Offset/Offset - 2-1/2" in/out
1978–1983 Chevrolet Malibu 40 Series - Offset/Offset - 2-1/2" in/out
1997–2022 Chevrolet Malibu  
1970–1988 Chevrolet Monte Carlo 1970–1977: 40-series (Offset/Offset) - 2-1/2" in/out
1978–1988: 40 Series - Offset/Offset - 2-1/2" in/out
1964–1987 Oldsmobile Cutlass 1978–1987: 40 Series - Offset/Offset - 2-1/2" in/out
1958–1977 Pontiac Bonneville 40 Series (Offset/Offset) - 2-1/2" in/out
1982–1986 Pontiac Bonneville 40 Series - Offset/Offset - 2-1/2" in/out
1959–1977 Pontiac Catalina 40 Series (Offset/Offset) - 2-1/2" in/out
1962–1987 Pontiac Grand Prix 1962–1977: 40 Series (Offset/Offset) - 2-1/2" in/out
1978–1987: 40 Series - Offset/Offset - 2-1/2" in/out
1964–1973 Pontiac GTO 40 Series (Offset/Offset) - 2-1/2" in/out
1964–1974 Pontiac LeMans 1964–1973: 40 Series (Offset/Offset) - 2-1/2" in/out
1964–1970 Pontiac Tempest 40 Series (Offset/Offset) - 2-1/2" in/out
  • Headshot of OPGI Employee
    Have a Question? Chat with an Expert or Call 1‑800‑243‑8355
    Mon‑Fri 8:00‑4:30 PT Experts are currently offline
  • Low Prices. Price Match Guarantee
  • GM Automotive Experts. We know car parts
  • Guaranteed Fitment. 100% factory accurate
  • Superior Selection. Largest selection of in-stock parts

Customers Who Viewed This Item Also Viewed

Reviews (1)

UH OH! Product reviews didn't load.
Please reload the page, or unblock our review partner Yotpo.com.
Muffler, Flowmaster, 40 Series, 2-1/2
Flowmaster Muffler, Flowmaster, 40 Series, 2-1/2", Offset Inlet/Outlet, 409S