Semi-Machined Detail:

Machined: Main surfaces, exhaust bolt pattern, intake bolt holes, valve guides, valve seats, valve spring seats, rocker stands and spark plug holes

Not Machined: Head bolt holes, dowel holes and pushrod holes

Same casting P/N 12480146

• Machined: Main surfaces, exhaust bolt pattern, intake bolt holes, valve guides, valve seats, valve spring seats, rocker stands and spark plug holes
• Not Machined: Head bolt holes, dowel holes and pushrod holes
• Same casting P/N 12480146

Machined: Main surfaces, exhaust bolt pattern, intake bolt holes, valve guides, valve seats, valve spring seats, rocker stands and spark plug holesChevrolet Performance