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Photo of Cyl Heads, AFR Mongoose Street, LS3 4-Bolt, 260/95cc, 69cc Chamber
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Air Flow Research

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

Vehicle Specific View fitment for 31 models
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Part# CH35731
Mfg# 1845
Sold As Pair
$2,672.99
List Price: $2,940.95
You Save $267.96

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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.

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Fully Assembled or Bare Heads

Fully CNC ported intake, exhaust & combustion chambers

AFR’s MONGOOSE LS3 Rectangle Port cylinder heads are 100% 5-AXIS CNC ported and made with A356 aluminum. All heads come with high quality components, such as titanium retainers and Pac Racing Springs. These are equipped with AFR's standard 3/4" thick deck, with thicker port and combustion surfaces. Reinforced rocker stud bosses, and thick wall runners are structural features for added strength and reliability. AFR stud girdles along with full roller arms are required. The assembled heads utilize titanium retainers, dual valve springs and premium grade components throughout. Available in a 260cc runner volume. Minimum bore sizing is 4.000” to accommodate intake valve clearance. Recommended operating up to 7000 RPM for street/strip builds.

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.
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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)

Find Item In These Catalogs

  • 2023 Cadillac 1936-1993 129
  • 2023 Cutlass, F-85 & 442 61-77 220
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
1978–1987 Buick Regal 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
1983–1987 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
1965–1976 Cadillac Calais 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1959–1996 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
1954–1996 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
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
1937–1976 Cadillac Series 65 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1987 Cadillac Series 67 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1987 Cadillac Series 70 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1987 Cadillac Series 72 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1936–1987 Cadillac Series 75 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1976–1996 Cadillac Seville 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
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
1978–1983 Chevrolet Malibu 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
1970–1988 Chevrolet Monte Carlo 260/95cc INT/EXH, 2.610"/1.540" valves - LS3, 4-bolt, 69cc chamber, angle plug
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
1961–1973 Pontiac LeMans 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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