AFR 12° LS3 Head 260cc, Fully CNC Ported, 4 BOLT, 69cc Chambers
AFR’s 260cc LS3 "Mongoose" heads feature 100% CNC ported intake, exhaust, and chambers, utilizing advanced engineering and flow techniques to deliver the most refined Rectangle Port head available today. Constructed from A356 aluminum castings and equipped with titanium retainers and premium components, these heads are designed for high-performance applications. They support 4.000” or larger bore engines up to 454 CI, operating at up to 7000 RPM. This product is 50-state street legal for 2007-2016 emission-controlled vehicles equipped with a General Motors 6.2L LS engine. AFR heads are also available bare—contact our tech line for details.
Basic Package Components
- 100% CNC Ported Combustion Chambers
- 100% CNC Ported Exhaust Ports
- 100% CNC Ported Intake Ports
- Competition 5-angle Valve Job
- 8mm Bead Lock Intake Valve, 2.165" x 5.200" Overall Valve Length (AFR #7214)
- 8mm Bead Lock Exhaust Valve, 1.600" x 5.205" Overall Valve Length (AFR #7212)
- PAC Racing Spring 1.270" OD Hydraulic Roller Dual Valve Spring, 155 lbs. on seat, .650" max lift, Max RPM 7000-7200 (AFR #8019)
- 7° Titanium Retainers 1.245" O.D x .885" I.D x .655" I.D (AFR #8512)
- 7° Bead Lock Valve Keepers (AFR #9007)
- Viton Valve Seals .600" O.D x .495" I.D (AFR #6612)
- Hardened Valve Spring O.D Locator 1.380" O.D x .570" I.D (AFR #8042)
- Ductile Iron Intake Valve Seats 2.200" O.D x 1.750" I.D x .375" Deep (AFR #9060)
- Ductile Iron Exhaust Valve Seats 1.650" O.D x 1.350" I.D x .375" Deep (AFR #9069)
- 8mm Bronze Valve Guides .502" O.D x 2.550" O.A.L (AFR #9053)
- Rocker Rail Stand (AFR #6040)
260cc Large Bore Competition Flow Chart
Test conducted at 28" of water (pressure) on Superflow 1020
Bore Size: 4.060", intake 3/4" radius plate exhaust, 1 3/4" curved pipe
| Lift (in.) |
.200 |
.300 |
.400 |
.500 |
.600 |
.650 |
.700 |
| Intake |
159 |
234 |
293 |
336 |
366 |
377 |
384 |
| Exhaust |
112 |
158 |
207 |
235 |
248 |
251 |
255 |
Specifications & Features
- Material: A356 Aluminum
- Intake Port Volume: 260cc
- Intake Port Dimensions: 2.610"H x 1.300"W x 7/16° Radius
- Intake Port Location: Stock
- Exhaust Port Volume: 95cc
- Exhaust Port Dimensions: 1.540" H x 1.760" W
- Exhaust Port Location: Stock
- Combustion Chamber Size: 69cc
- Valve Cover Bolt Pattern: Center Bolt
- Valve Angle: 12°
