Super 23 Assembled Aluminum Cylinder Heads

The Trick Flow® Super 23® 195 Cylinder Heads are engineered for Small Block Chevrolet engines, offering performance that closely matches CNC-ported heads at a more accessible price point. These assembled aluminum heads are ideal for 302 to 406 cubic inch engines, featuring high-velocity, small cross-section intake runners designed to optimize both low-rpm torque and high-rpm horsepower. The Fast As Cast® runners provide near-CNC-ported flow and performance. The heads boast modern CNC-profiled chambers for improved combustion efficiency, reducing the need for excessive ignition timing and minimizing detonation risk. Enhanced A356-T61 castings feature thicker decks for added strength and durability, improved 3/8" pushrod clearance, and CNC-profiled intake port entry. Additional features include a competition multi-angle valve job, angled spark plugs, and raised valve cover rails for increased rocker arm clearance and reduced oil leak potential. These cylinder heads come fully assembled with premium components, including stainless steel intake valves (2.020 in.), exhaust valves (1.600 in.), bronze valve guides, 7° machined locks, and chromoly retainers. They are equipped with dual PAC Racing valve springs (1.460" O.D.) suitable for hydraulic roller cams with a maximum lift of 0.600 in. Guideplates and rocker arm studs are included, but rocker arms and nuts are sold separately. They are sold individually. These cylinder heads are a direct-fit, high-performance replacement for factory heads and accept most original accessories. They are emissions-legal under CARB E.O. #D-747-1 for 1995 and earlier GM vehicles with Chevy 262-350 engines. Important fitment notes include: these heads only fit engines with a 4.000 in. bore or larger, they have a 1987-1995 intake manifold bolt pattern, and require drilling steam holes into the head on 400 c.i. applications. They will not fit LT1 engines, nor will they fit 1986-1991 Chevrolet Corvettes with factory aluminum heads.