I don't know what to tell you except what are you arguing about? I guess you can have it your way if you want, but GM calls it "Fast Burn", so I suppose if GM calls it "Fast Burn" everybody but you can call it "Fast Burn", do you think?
For a head that you want to say is not a "Fast Burn" design it sure runs good with I guess what y'all are saying is not enough spark advance, and if it has any more than "not enough" it makes less power.
Large-Port Vortec Bowtie Head Assembly
19331472
Product Details
VORTEC BOWTIE CYLINDER HEADS
Vortec Bowtie cylinder heads are the most powerful cast-iron heads offered by Chevrolet Performance. These upgraded production cylinder heads are ideal for 400-450 horsepower street and racing (great for circle track applications) engines. Vortec Bowtie cylinder heads come with bigger valves, a thicker deck surface and 66cc combustion chambers. The heads provide outstanding low-lift flow numbers (the more air you flow, the more potential power) and
Fast Burn performance all in an affordable, cast-iron head.
Vortec Bowtie Cylinder Head Technical Notes:
• Cast-iron Large Runner Cylinder Head
• 66cc combustion chambers
• 0.450" deck thickness
• Hardened exhaust valve seats
• Machined for 2.000"/1.550" valves
• Maximum 0.530" valve lift (without modifications)
• Straight spark plug design
• No heat risers
• Drilled and tapped for 7/16"-14 screw-in studs
• Dual bolt patterns for Vortec and early style intake manifolds (early model P/N 10051103; Vortec intakes P/N 12366573, 12496820, 12496821, 12496822 or 12489371)
• Use intake gasket P/N 89017465 for Vortec intakes or dual pattern intake gasket P/N 19301685 for early model intakes or Vortec design intake manifolds
• Dual bolt patterns for perimeter-style and center-bolt valve covers
• Vortec intake manifold three-step torque specs: 2 lb.-ft.; 9 lb.-ft.; 11 lb.-ft.
Large-Port Vortec Bowtie Head Assembly
• Completely assembled, ready to bolt-on
• Improved air flow (281 cfm @ 0.600")
• 225cc intake ports
• 77cc exhaust ports
• 65cc combustion chambers
• Use Fel-Pro® P/N 1470 exhaust gasket (minor trimming may be necessary)
• Bare head P/N 19331473, available separately
This head is assembled with the following components:
12555331 Intake valves (4)
19301708 Valve spring retainers (8)
12551313 Exhaust valves (4)
19301709 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