BB-3 Xtra aluminum cylinder heads combine the benefits of a 2ø rolled valve angle and redesigned exhaust ports. Cast from rigid A-356 aluminum, heads are offered in two versions; standard BB-3 Xtra has CNC-ported combus-tion chambers, blended valve bowls and matched ports, while the BP BB-3 Xtra is 100% CNC-ported. Bare or fully assembled heads are sold individually.
- Cylinder Head Style:
- Assembled
- Cylinder Head Material:
- Cast aluminum
- Cylinder Head Finish:
- Natural
- CNC-Machined Combustion Chamber:
- Yes
- Combustion Chamber Volume (cc):
- 119cc
- Combustion Chamber Style:
- Heart
- CNC-Machined Intake Runner:
- Yes
- Intake Runner Volume (cc):
- 366cc
- Intake Port Shape:
- Rectangular
- Intake Port Location:
- Standard
- Intake Valve Angle:
- 24/4 degree
- CNC-Machined Exhaust Runner:
- Yes
- Exhaust Runner Volume (cc):
- N/A
- Exhaust Port Shape:
- Round
- Exhaust Port Location:
- Standard
- Exhaust Valve Angle:
- 15/4 degree
- Intake Valves Included:
- Yes
- Intake Valve Diameter (in.):
- 2.300 in.
- Exhaust Valves Included:
- Yes
- Exhaust Valve Diameter (in.):
- 1.880 in.
- Valve Type:
- N/A
- Maximum Valve Lift (in.):
- 0.850 in.
- Valve Springs Included:
- Yes
- Valve Spring Type:
- Dual W/Damper
- Outside Diameter of Outer Spring (in.):
- 1.645 in.
- Valve Guides Included:
- Yes
- Valve Guide Material:
- Phosphorous bronze
- Valve Seats Machined:
- Yes
- Valve Seat Material:
- Ductile iron
- Valve Seat Machine Style:
- 5-angle
- Retainers Included:
- Yes
- Retainer Material:
- Titanium
- Valve Stem Seals Included:
- Yes
- Valve Stem Seal Style:
- PTFE Positive stop
- Locks Included:
- Yes
- Lock Style:
- 10 degree
- Camshaft Style:
- Solid roller
- Spark Plug Style:
- Straight
- Guideplates Included:
- Yes
- Guideplate Pushrod Size:
- 3/8 in.
- Rocker Arm Studs Included:
- Yes
- Rocker Arm Nut Thread Size:
- 7/16-20 in.
- Accessory Bolt Holes Drilled:
- Yes
- Valve Cover Mounting Style:
- Perimeter bolt
- Heat Crossover:
- No
- Steam Holes Drilled:
- No
- Oiling Style:
- Through pushrod
- Machined for O-Ring:
- No
- Quantity:
- Sold individually.
- Make:
- Chevrolet
- Engine Family:
- Chevy big block Mark IV
- Engine Sizes:
- 6.5L/396-7.4L/454
- Years:
- 1965-1990
- Engine Family:
- Chevy big block Gen V
- Years:
- 1991-1995
- Engine Family:
- Chevy big block Gen VI
- Years:
- 1996-2000
- Engine Sizes:
- 7.4L/454
