Manufacturer's Part Number:
Part Type:
Product Line:
Combustion Chamber Volume (cc):
69
Intake Runner Volume (cc):
255cc
Exhaust Runner Volume (cc):
87cc
Cylinder Head Style:
Assembled
Cylinder Head Material:
Cast aluminum
Camshaft Style:
Hydraulic roller
Intake Port Shape:
Rectangular
Intake Valve Diameter (in.):
2.165 in.
CNC-Machined Combustion Chamber:
Yes
CNC-Machined Intake Runner:
Yes
CNC-Machined Exhaust Runner:
Yes
Combustion Chamber Style:
Heart
Intake Port Location:
Standard
Exhaust Port Shape:
Oval
Exhaust Port Location:
Standard
Spark Plug Style:
Angle
Intake Valves Included:
Yes
Exhaust Valves Included:
Yes
Exhaust Valve Diameter (in.):
1.600 in.
Valve Springs Included:
Yes
Maximum Valve Lift (in.):
0.650 in.
Outside Diameter of Outer Spring (in.):
1.300 in.
Damper Spring Included:
No
Number of Springs Per Valve:
Dual
Retainers Included:
Yes
Retainer Material:
Titanium
Locks Included:
Yes
Lock Style:
7 degree
Valve Stem Seals Included:
Yes
Rocker Arm Studs Included:
No
Rocker Arms Included:
No
Rocker Arm Nuts Included:
No
Guideplates Included:
No
Accessory Bolt Holes Drilled:
Yes
Intake Valve Angle:
12
Exhaust Valve Angle:
12
Valve Guides Included:
Yes
Valve Guide Material:
Powdered metal
Valve Seats Machined:
Yes
Valve Seat Machine Style:
3-angle
Valve Seat Material:
Ductile iron
Cylinder Head Color:
Natural
Steam Holes Drilled:
No
Oiling Style:
Through pushrod
Machined for O-Ring:
No
Heat Crossover:
No
Remanufactured:
No
Quantity:
Sold individually.
Notes:
These cylinder heads can only be used with a minimum bore diameter of 4.000 in. Includes new rocker arm rail mounts for use with LS3 1.7 ratio rocker arms. OEM rocker arm rail mounts will not work with these heads.
CARB EO Number(s):
Emissions:
California EO Approved
Trick Flow engineers used the best features of OEM GM LS3 and LS7 cylinder heads, combined with their own race-winning engineering and technology, to create the GenX® 255—the ultimate ultimate square port LS cylinder head for 4.000" and larger bore engines. The heads feature fully CNC Competition Ported runners with a premium high resolution surface finish for maximum airflow and performance potential. Stock LS3 ports accommodate LS3-style intake manifolds and LS9/LSA blower assemblies. The valve angles have been changed from 15° to 12° to increase piston-to-valve clearance and allow the use of larger camshafts. The coolant holes through the head deck were redesigned to work with all LS head gasket and engine block combinations. GenX 255 heads are available with standard or 6-bolt per cylinder mounting patterns.
Trick Flow GenX 255 cylinder heads are emissions-legal under CARB E.O. #D-747 for 2007-present GM vehicles with 6.2L engines. They are available fully assembled or as bare castings. Sold individually.
