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Air Flow Research

Cyl Heads, AFR Mongoose Street, LS3 4-Bolt, 260/95cc, 69cc Chamber

Part# : CH35731
Mfg#: 1845
Sold As: Pair
Ship Size: Oversize 3
$2,751.99
List Price: $3,027.95
You Save $275.96

Color Variation

Due to variations in monitor settings, some colors on this page may appear slightly different from GM originals. In addition, due to color differences in the original GM dye lots, interior product colors may vary slightly.

Vehicle Specific View fitment for 62 models
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LS3 260cc 4-Bolt Mongoose Street Heads by Air Flow Research®

100% CNC-ported A356 LS3 Mongoose heads use 260/95cc ports, 69cc chambers and a 12-degree valve angle.

Air Flow Research® 260cc LS3 Mongoose heads use A356 aluminum castings with 100% CNC-ported intake, exhaust and combustion chambers plus a Competition 5-angle valve job. Designed for 4.000-inch-and-larger bore LS combinations up to 454 ci and about 7000 RPM, they use 260cc intake and 95cc exhaust ports, 69cc chambers, a 12-degree valve angle and .750-inch deck. This 4-bolt version is available assembled or bare depending on configuration; sold as a pair.

• Air Flow Research® 260cc LS3 Mongoose series • 100% CNC-ported airflow surfaces • 260cc intake / 95cc exhaust ports • 69cc chamber; 12-degree valve angle • 4.000-inch minimum bore / .750-inch deck • 4-bolt configuration; sold as a pair

Notes

  • GM rocker arms are not designed/engineered to accommodate aftermarket cams or higher spring pressures. At a minimum, AFR recommends using Bushing Trunion Kit on their LS1/LS3 heads. Without proper parts you will experience accelerated guide wear.
  • AFR recommends a minimum depth of .080" on the intake valve and .100" on the exhaust with radical clearance of .020" minimum around the perimeter of each valve. The valve pocket must also be addressed.
  • AFR valve spring installed high spec is +/- .015". To ease installation with 1.550" O.D or larger springs, 12 pt. head bolt or studs are recommended for extra clearance. Beveled or ground washer might be needed.
  • AFR heads come with proper guide clearance (.0012"-.0016" for most applications, boosted/nitrous applications might require additional clearance and it is the customer's responsibility to verify proper clearance in these applications).
  • Check pushrod clearance with heads place on the block before final assembly, larger pushrods will not fit without clearancing and is not recommended since some areas are very thin. AFR recommends the use of .120" thick-wall pushrods.
  • If you're using a high volume or high pressure oil pump it can submerge the valve seals in oil causing smoke or oil consumption.
  • Flat or angle mills could affect flow numbers and might require a thicker intake gasket.
  • Shaft mount rockers might require additional clearance for proper pushrod fitment, do not clearance the push rod area as the wall is .060" thick.
  • Use full roller rocker arms, roller tip rockers with stock style bodies are NOT recommended.
  • This item is not eligible for any further discounts or promotional pricing.
  • This item is Oversize 3, and is excluded from free ground shipping.
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This product is covered under a CARB EO and is legal for sale and use in all 50 states. Learn More

CARB EO Number: D-250-5 (pdf)

We aim to provide accurate and complete product information. If you notice anything incorrect, missing, or unclear, please let us know.
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 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1984–1987 Buick Grand National 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1976–1987 Buick Regal 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1978–1987: 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1963–1976 Buick Riviera 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1961–1972 Buick Skylark 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1983–1986 Buick T-Type 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1938–1993 Cadillac 60 Special 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
2013–2019 Cadillac ATS 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1965–1976 Cadillac Calais 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
2003–2019 Cadillac CTS 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1959–2005 Cadillac DeVille 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1953–2002 Cadillac Eldorado 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1999–2000 Cadillac Escalade 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
2002–2023 Cadillac Escalade 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
2002–2013 Cadillac Escalade EXT 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1965–1996 Cadillac Fleetwood 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1951 Cadillac Series 60 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1946–1964 Cadillac Series 60 Fleetwood  
1936–1951 Cadillac Series 61 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1937–1976 Cadillac Series 62 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1951 Cadillac Series 63 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1937–1938 Cadillac Series 65 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1942 Cadillac Series 67 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1937 Cadillac Series 70 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1940 Cadillac Series 72 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1942 Cadillac Series 75 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1946–1964 Cadillac Series 75 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1946–1964 Cadillac Series 75 Fleetwood  
1976–2004 Cadillac Seville 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
2005–2011 Cadillac STS 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
2004–2009 Cadillac XLR 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1947–1955 Chevrolet Advance Design  
1969–1994 Chevrolet Blazer 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 Chevrolet C10 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 Chevrolet C20 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 Chevrolet C30 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1964–1977 Chevrolet Chevelle 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1969 Chevrolet Corvair 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1961–1965 Chevrolet Corvair 95 FC 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1959–1960 Chevrolet El Camino 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1964–1987 Chevrolet El Camino 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 Chevrolet K10 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 Chevrolet K20 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1977–1987 Chevrolet K30 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1978–1983 Chevrolet Malibu 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1997–2022 Chevrolet Malibu  
1970–1988 Chevrolet Monte Carlo 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1995–2007 Chevrolet Monte Carlo 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1991 Chevrolet Suburban 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1955–1959 Chevrolet Task Force 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1955–1959 GMC Blue Chip 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 GMC C15/C1500 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 GMC C25/C2500 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 GMC C35/C3500 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1978–1987 GMC Caballero 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1970–1991 GMC Jimmy 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 GMC K15/K1500 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1987 GMC K25/K2500 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1977–1987 GMC K35/K3500 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1947–1955 GMC New Design 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1971–1977 GMC Sprint 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1960–1991 GMC Suburban  
1961–1988 Oldsmobile Cutlass 1961–1977: 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1958–1986 Pontiac Bonneville 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1959–1977 Pontiac Catalina 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1962–1987 Pontiac Grand Prix 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1964–1973 Pontiac GTO 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1961–1981 Pontiac LeMans 1961–1973: 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1961–1970 Pontiac Tempest 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
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