12691728
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

Small-Block Cylinder Heads
Part Number: 12558060
Description: Vortec
Casting Number: 10239906 or 12558062
Material: Iron
Port Size: 170
Port Type: Vortec
Valve Angle: 23
Chbr CC's: 64
Int Vlv: 1.940
Exh Vlv: 1.500
Exh Port: LT4
Plug Type: Straight
Heat Riser: No
Rocker Stud: Press
Notes: Assembly