Product Description
Michigan Motorsports 11 Degree 260cc CNC Rectangle Port LS3 Heads
Fits 1997-2013 LS-Based Engines with Rectangle Port Intake Manifolds LS3 L99 L76 L77 L92 L96 LSA
These fully CNC machined cylinder heads from Michigan Motorsports feature a revised 11 Degree valve angle for unmatched performance compared to standard 15 degree LS heads. Designed for 4.000"+ bore engines with LS3 (also known as Rectangle Port) intake manifolds. Extra-thick deck surfaces help alleviate head gasket sealing issues in power-adder applications. Great for Naturally Aspirated, Boosted, or Nitrous applications. The 260cc intake port has been flow bench tested to over 370cfm and is ideal for feeding the airflow demands of high RPM stock bottom end combinations or larger displacement stroker engines. Heads come fully assembled with stainless steel valves and polished PAC dual valve springs with titanium retainers suitable for most hydraulic roller applications. These are 6 bolt castings to fit aftermarket blocks but work great on factory 4-bolt blocks as well.
Features:
- 6 bolt pattern: Can be used on Aftermarket 6 bolt blocks or Factory 4 bolt blocks
- 11 Degree valve angle for improved performance compared to typical 15 degree LS heads
- 68cc CNC Machined Combustion Chamber
- 260cc CNC Ported Intake Runner
- Hand blended valve job
- Extra Thick.750"+ Deck Surfaces
- PAC Dual .660" Valve Springs with Titanium Retainers Installed
- 2.165" Stainless Intake Valves, 1.600" Stainless Exhaust valves
- Hollow Stem Intake Valve upgrade available (see options)
- Maximum Recommended Valve Lift: .650"
- Billet rocker stands included
- Fits 4.000" and larger bore blocks
- Requires head gaskets with a minimum 4.100" bore size. LS9 Gaskets recommended for most factory-block applications.
- Clearance for 3/8" Diameter Pushrods. Depending on camshaft, lifter and rocker arm selection, typical required pushrod length will be in the 8.100-8.250" range.
- Sold/Priced as a pair
Developed in conjunction with Hooper's Heads in Houston, TX, bringing decades of experience in high end race engine airflow and applying it to a budget friendly, easy to bolt-on head package.
