Mast Motorsports Rectangular Port LS7 12 Degree 6-Bolt Large Bore CNC Assembled (4.125″ Bore)

• Utilizes the Gen IV LS7 valve-train and intake manifold.
• Designed for any new Gen IV short-block with 4.125″ bore or larger.
• Uses a 2.200″ intake valve and 1.600″ exhaust valve
• Has a 280cc intake port
• Has a deck thickness of .750″
• Has a 70cc Combustion Chamber Standard

Each Mast Black Label cylinder head assembly includes:

• A fully CNC machined Mast Black Label aluminum cylinder head
• Mast nitrided & micro finished .700″ Lift Dual Springs
• Mast lightweight stainless steel intake & exhaust valves
• Mast lightweight steel retainers
• Mast machined locks

NOTE: Gaskets, valve covers, rocker arms and pushrods not included

Flow Data w/4.125″ Bore Plate

Lift Intake Exhaust

0.100 76 65

0.200 163 118

0.300 245 171

0.400 307 212

0.500 350 229

0.600 379 245

0.650 388 247