19300955 NEW
Fast Burn Aluminum Cylinder Head Assembly

• CNC-machined aluminum performance cylinder head
• Completely assembled with 2.000"/1.550" valves
• 210cc intake port, roof raised .240"
• 78cc D-shaped exhaust ports, raised .200" – requires Fel-Pro® exhaust gasket P/N 1470 (may require minor trimming)
• 62cc combustion chamber, .400" deck (can be milled to .060")
• No heat riser
• Angled spark plugs (5/8” hex, 3/4" reach, tapered plugs)
• 1.48" valve spring seat diameter
• Use head gaskets with stainless steel fire rings
• Raised, machined rocker rails
• .530" maximum valve lift (without modifications)
• Screw-in studs (3/8" top, 7/16" bottom)
• New "time-serts" prevents oil migration through rocker studs
• Dual bolt patterns for perimeter-bolt and center-bolt valve covers
• Dual bolt patterns for Vortec and early-model intake manifolds
• Use bare head P/N 19300956
• Use production intake gasket P/N 19301685

This head is assembled with the following components:
12555331 Intake valves (4)
19301708 Valve spring retainers (8)
12551313 Exhaust valves (4)
19307709 Valve stem key (16)
12625033 Valve springs (8)
12552126 Valve rocker arm studs (8)
19301707 Valve spring seats (8)
10168519 Valve guides (8)
10212810 Valve stem seals (8)
12346004 Valve rocker arm stud sealer

Small-Block Cylinder Heads:
Part Number: 19300955
Description: Fast Burn ZZ5
Casting Number: 12367712
Material: Alum
Port Size: 210
Port Type: Vortec
Valve Angle: 23
Chbr CC`s: 62
Int Vlv: 2.000
Exh Vlv: 1.550
Exh Port: LT4
Plug Type: Angled
Heat Riser: No
Rocker Stud: Screw-in
Notes: Assembly