Flo-Tek Recommended Setup:
Header – Based on Chassis-2 1/8”
Rocker Arms – Isky Roller Rockers 204-96 1.75:1 or Equivalent
Intake Manifold – Victor JR or Super Victor

A powerful, out-of-the-box cylinder head design matched with an outstanding, unbeatable casting technology. We are here to tell you…this BBC head does just that! FLOTEK Aluminum Cylinder Heads are a great choice for out of the box horse power. These FLOTEK Cylinder thick Deck Design and High Capacity water jackets that makes them a reliable choice for street or strip applications.

The FLO-TEK BBC 320 takes stock pistons and has raised valve cover rails. The BBC 320 Exhaust Port location is raised .500. 


HYDRAULIC ROLLER (Part# 305-6056) – 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# 305-6058) – 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# 305-5059) – 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
Intake Port GasketFel Pro 1252-3 (320) Fel Pro 1211 (360)
Exhaust Port GasketFel Pro 1404
Head GasketFel Pro 1017-1 (4.500) 1057 (4.630)
Head Bolts & StudsARP 135-3703 (12pt) 135-3606 (6pt) 235-4303 (Stud)
Stud GirdleHarland Sharpe G1114 (7/16)
Suggested ManifoldVictor Jr, Super Victor
Spark Plug Starting Range14mm (.750) Accel #416
Intake Port Volume320 cc
Exhaust Port Volume128cc
Combustion Chambers133cc
Max Spring Pocket Diameter1.725” O.D.

Basic Package Components:
Intake Valve Hydraulic2.250 +.250
Exhaust Valve Hydraulic1.880 Stock Length
Intake Valve Solid2.250 +.250
Exhaust Valve Solid1.880 +.100
RetainersHardened Chrome Moly
Guide PlatesDART 2700123-4/PC-4247
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
Valve Locks7 Degree and 10 Degree

Part Specification

Flo-Tek Cylinder HeadID#Part Number
BBC 320 Bare850134007112306-500
BBC 320 Hyd Roller Assembled850134007686305-6056
BBC 320 Solid Roller Assembled850134007693305-6058
BBC 320 Solid Roller PAC Assembled850134007570305-5059

Flow Chart


Dimensions & Weight

Big Block Chevy Bare32 Pounds
Big Block Chevy Assembled40.6 Pounds

Additional information

Weight 40.6 lbs
Dimensions 24.5 × 10.5 × 9 in

BBC 320 Bare (306-500), BBC 320 Hyd Roller Assembled (305-6056), BBC 320 Solid Roller Assembled (305-6058), BBC 320 Solid Roller PAC Assembled (305-5059)