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 (Part# 290-6056) – PSK573-1-10 Up to .725 Lift CL 225# @ 1.90 OP 530# @ 1.28 C/BIND 1.18 O.D 1.55” Dual W/D I.D. 0.75

SOLID ROLLER (Part# 290-6058)– PSK623-1-10 Up to .750 Lift CL 290# @ 1.90 OP 625# @ 1.30 C/BIND 1.17 O.D 1.62” Dual W/D I.D. 0.74

SOLID ROLLER (Part# 290-5059) – PAC1224 Up to .850 Lift CL 275# @ 2.00 OP 810# @ 1.150 C/BIND 1.100 O.D 1.62” Dual I.D. 0.85


  • 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 Machining1.750″ 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 Hydraulic2.30 +.250
Exhaust Valve Hydraulic1.880 Stock Length
Intake Valve Solid2.30 +.250
Exhaust Valve Solid1.880 +.100
Head GasketFel-Pro #1017
Intake GasketMr. Gasket 107
Exhaust GasketMr. Gasket 5911
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
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
Valve Locks7 Degree and 10 Degree
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 Hyd Roller Assembled850134007648290-6056
BBC 290 Solid Roller Assembled850134007655290-6058
BBC 290 Solid Roller PAC Assembled850134007556290-5059

Flow Chart


Dimensions & Weight

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

Additional information

Weight 43 lbs
Dimensions 22.25 × 8.5 × 5 in

BBC 290 Bare (290-500), BBC 290 Hyd Roller Assembled (290-6056), BBC 290 Solid Roller Assembled (290-6058), BBC 290 Solid Roller PAC Assembled (290-5059)