These Trick Flow GenX® 205 cathedral port cylinder heads are fully CNC-machined to significantly increase the performance GM’s 4.8L/5.3L/5.7L LS engines. Trick Flow engineers altered the valve angles from 15° to 13.5° to decrease valve shrouding, increase mid-lift airflow, and improve rocker arm-to-valve cover clearance. Top-of-the-line CNC Competition Ported runners have a premium high resolution surface finish for maximum flow and performance. The spark plugs were relocated in the CNC-profiled combustion chambers to enhance mid-lift airflow and increase the rigidity of the casting for extreme horsepower applications. Material was added at the rocker arm mounting points to increase high-rpm valvetrain stability.
Trick Flow GenX 205 cylinder heads are emissions-legal under CARB E.O. #D-747 for 1997-present GM vehicles with 4.8L, 5.3L, 5.7L, and 6.0L engines. They are available fully assembled or as bare castings. Sold individually.