Mast: LS7 265cc 4.000" Cylinder Heads [Camaro Corvette CTS V, LS7]

Mast Motorsports


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Trying to improve on the best factory small-block cylinder heads ever built is no small endeavor. And yes, GM's 12-degree LS7 castings are the best small-block heads of all time-regardless of engine make-trumping even the legendary Ford Cleveland heads. With a full CNC rubdown, monster 2.20/1.61-inch valves, and raised 270cc intake ports to go along with a flat 12-degree valve angle, factory LS7 heads flow 360 cfm out of the box. That's big-block territory, and at a hair less than $3,000 for a set of fully assembled LS7 heads from your friendly GMPP distributor, they're an exceptional value as well. So naturally, we were quite intrigued when Mast Motorsports announced it had just developed its own 265cc LS7 castings that outflows the factory design in a smaller bore.

LS7 performance for your LS3 LS2 or other 4.000" or larger bore LS engine!  Ideal on stroked engines, this LS7 265 head was designed from the ground up.

  • Utilizes the Gen IV LS valve-train and intake manifold
  • Designed for any new Gen IV short-block with 4.000" bore or larger
  • Uses a 2.165" intake valve and 1.600" exhaust valve
  • 11 Degree Valve angle
  • Has a 265cc intake port
  • Has a deck thickness of .750"


Flow Data w/4.065" Bore Plate
Lift Intake Exhaust
0.100 82 61
0.200 151 119
0.300 230 188
0.400 292 219
0.500 332 236
0.600 352 251
0.650 360 254
0.700 365 260
0.800 369 263
0.850 370  
0.900 371

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