FLOTEK’s medium sized 290cc oval port cylinder head with 112 combustion chamber is recommended for moderate street or street/strip big block Chevys with displacements up to 509 cubic inches, operating at or below 6500 RPM. Capable of flowing 367 CFM at 0.600″ of lift; tested on Super Flow Bench 1020. It may be necessary to slightly clearance or modify the the piston due to our more efficient heart shaped combustion chamber design with some domed aftermarket pistons, most of the newer designed dome profiles will clear. FLOTEK recommends material be removed from the piston and not the cylinder head. Our combustion chamber shapes are very critical to flow and altering the cylinder head can unfavorably affect flow and power performance. It is the customer’s responsibility to verify proper piston to head clearance. Heads are designed for 3/8″ pushrods. Larger pushrods will not fit without clearance and is not recommended since some areas are very thin. FLOTEK recommends the use of .120″ thick-wall pushrods.


HYDRAULIC ROLLER (.600 Lift) – Spring Kit: PSK-637-1-7 Hydraulic Roller Dual Valve Spring 1.50″ O.D., Max RPM 6500-6700
Valve Spring: PSK573-1-10 CL 225# @ 1.90 OP 530# @ 1.28 C/BIND 1.18

SOLID ROLLER (.700 Lift) – Spring Kit: PAC 1228 Roller Valve Race Spring 1.625″ O.D Solid Roller Valve Spring, Max RPM 7200-7400
Valve Spring: PSK623-1-10 CL 290# @ 1.90 OP 625# @ 1.30 C/BIND 1.17

SOLID ROLLER (.800 Lift) – Spring Kit: PAC 1248 Roller Valve Race Spring 1.645″ O.D Solid Roller Valve Spring, Max RPM 7200-7400
Valve Spring: PAC1224 CL 275# @ 2.00 OP 810# @ 1.150 C/BIND 1.100

  • Headers will bolt on in most applications. Some may have interference.
  • Recommendations: Hooker Super Comp Headers
  • Stock Bolt Spread
  • May be necessary to use lowered motor mounts


Specifications, Features & Optional Supporting Components

Head Bolt Torque75 Ft Lbs w/ oil
Rocker Stud Torque50 Ft Lbs w/ oil
Stud GirdleHarland Sharpe G1114 (7/16)
Intake Port Volume290 cc
Intake Port Dimension2.030″H x 1.830″Wx1/2 Radius
Intake Port LocationStock
Exhaust Port Volume135cc
Exhaust Port Dimension1.770″H x 2.010″W
Exhaust Port Location.375″ Raised
Combustion Chamber Size112cc
Valve Cover Bolt PatternPerimeter Bolt
Valve Angle24°/4° Int, 15°/4° Exh
Valve Spring Pocket Diameter1.725″ O.D
Max Valve Spring Pocket Machining1.725″ O.D
Deck Thickness.750″
Minimum Bore Diameter4.250″
Flat Mill.006″ per cc/ Maximum 102cc
Angle Mill*.009″ per cc/ Maximum 97cc
Minimum Cross Sectional Area2.895 sq. in.
Spark Plug Dimensions14mm x .750″ w/ Gasket Seat

*Note: Angle Mills might require a .120″ Thick intake gasket

Recommended Components:
Intake Valve .6002.250 .100
Exhaust Valve .6001.880 .100
Intake Valve .7002.250 .250
Exhaust Valve .7001.880 .100
Intake Valve .8002.250 250
Exhaust Valve .8001.880 .100
Head GasketFel-Pro #1047 (Mark V and VI), Fel-Pro #1017-1 (Mark IV)
Head BoltsARP 135-3703 (Mark IV), ARP 135-3707 (Mark V)
Head StudsARP 235-4713
Head Bolt WashersManley
7/16 Stud Mount Rocker Arms1.7 Ratio (For Optimized Geometry)
Suggested ManifoldVictor Jr, RPM Performer
Spark Plug Starting RangeAutolite 3924
11/32″ Intake Valve2.250″ x 5.500″ O.A.L
11/32″ Nail Head Exhaust Valve1.880″ x 5.450″ Overall Valve Length
Racing Springs#1940 1.550″ O.D. Hydraulic Roller Dual Valve Spring
Manley 10° Steel Retainers1.500″ O.D. x 1.120″ I.D. x .705″ I.D.
Valve Locks with lashcap recess10° 11/32″
Rocker Exhaust StudsARP 7/16″
Rocker Intake StudsARP 7/16″
Guide PlatesDART 2700123-4/PC-4247
Valve Seals11/32″ Viton
Hardened Valve SpringI.D Locator 1.550″ O.D x .780″ I.D
Intake Valve Seats2.450″ O.D x 1.950″ I.D x .375″ Deep
Exhaust Valve Seats2.000″ O.D x 1.580″ I.D x .375″ Deep
11/32″ Intake Bronze Valve Guides502″ O.D x 2.10″ O.A.L
11/32″ Exhaust Bronze Valve Guides502″ O.D x 2.25″ O.A.L
Valve Locks .6007 Degree Valve Locks
Valve Locks .700/.80010 Degree Valve Locks
Rocker StudMust have Clearance for Valve Spring Retainers
Valve SealsViton Positive Seals
Spring CupHardened Steel Cups
Intake Valve SeatPowder Metal
Exhaust Valve SeatPowder Metal
Bronze Valve GuidesManganese Bronze

Part Specification

Flo-Tek Cylinder HeadID#Part Number
BBC 290 Bare850134007433290-500
BBC 290 Assembled .600 lift850134007402290-5056
BBC 290 Assembled .700 lift850134007419290-5057
BBC 290 Assembled .800 lift850134007426290-5058

Flow Chart


Dimensions & Weight

Big Block Chevy Bare32.2 Pounds
Big Block Chevy Assembled40.8 Pounds

Additional information

Weight 43 lbs
Dimensions 22.25 x 8.5 x 5 in

Chevy BBC 290 Bare (290-500), Chevy BBC 290 .600 Lift Assembled (290-5056), Chevy BBC 290 .700 Lift Assembled (290-5057), Chevy BBC 290 .800 Lift Assembled (290-5058)