VORTEC CYLINDER HEADS
An easy way to gain 20-40 horsepower on any 1955-and-newer Small-Block Chevrolet V-8 (except later-style LT1/LT4 engines with reverse-flow cooling) is by installing a set of Vortec cylinder heads. These value-priced cast-iron cylinder heads use modified combustion chambers and high velocity port technology to provide improved performance. Vortec cylinder heads significantly outflow non-Vortec service replacement cylinder heads and earlier OEM cast-iron heads. These cylinder heads are ideal for applications up to 350 horsepower, but they require Vortec-specific intake manifolds.
Cast-iron Vortec Cylinder Head Assembly
• Completely assembled with 1.940"/1.500" valves
• Uses bare head 12529093
• 64cc combustion chamber
• Straight spark plugs
• No heat risers
• Requires Vortec-specific intake manifold
• Camshafts with more than 0.475" lift require machining valve guide bosses and checking valve seal to valve spring retainer clearance
• Can be machined for 2.020"/1.600" valves
• Rocker arm studs can be pinned or drilled and tapped to 3/8"
• Valve spring seat diameter is 1.280"
• Casting number 10239906 or 12558062
This head is assembled with the following components
10241743 Intake Valves
10241744 Valve Spring Retainer
12550909 Exhaust Valves
10212810 Intake Seals
10212811 Valve Springs
12564852 Exhaust Seals
24503856 Valve Locks
California Proposition 65 Warning