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Item #: 12558060
Reg. Price: $420.65
Our Price: $356.71
Quantity:
 

Description 

America's favorite high performance cast iron small-block cylinder head offers big power and bigger value. The Vortec cylinder head's fast burn combustion chamber and high velocity ports combine to produce big horsepower out of the box. The Vortec head can be midly ported for additional performance and can be milled up to .040" for increased compression ratio. The Vortec head uses 1.94" intake valves and 1.50" exhaust valves to compliment the high velocity port design. The Vortec head out-flows the bow-tie head out of the box and is a 20 to 40 horsepower bolt on increase over earlier cast iron small-block heads. The Vortec requires a Vortec style intake manifold due to its improved manifold mounting flange and gasket design and raised intake ports. It is not recommended that the heads be modified to accept early design intake manifolds. Manifolds available are P/N12366573, 12496820, 1249621, 12496822. Vortec heads fit all small-block Chevrolet engines produced 1955 to present, excluding LT1/LT4 reverse coolant flow engines and current LS1 style engines. Heads come completely assembled with valves, springs, retainers, and 3/8" rocker studs. Requires the use of self aligning rocker arms. Technical Notes: The maximum camshaft lift is .475". The valves seats in these heads can be machined to 2.02" intake and 1.60" exhaust. The rocker arm studs can be pinned or drilled and tapped 3/8". (Casting P/N 10239906 or 12558062.)
Technical Note:

Do not use a camshaft with more than .0475" lift with this Vortec head with out re-machining the valve guide bosses or you will crush the valve stem seals. A larger camshaft maybe used when you machine the top of the valve guide bosse. When using a camshaft with lift over .475, you must check valve seal to valve cap clearance. The valves seats in these heads can be machined to 2.02" intake and 1.60" exhaust. The rocker arm studs can be pinned or drilled and tapped 3/8". Valve spring seat dia. is 1.48" (Casting P/N 10239906 or 12558062.)

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