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Flo-Tek 203505 Small Block Ford Aluminum Cylinder Head

SAME DAY SHIPPING! Order within the next 9 hours 36 minutes and receive same day shipping

Material Type:
Sold in Quantity:
MFG. Part #:
Intake Runners:
180 cc
Exhaust Runners:
62 cc
Combustion Chamber:
Cylinder Head Style:
Spark Plug Style:
Intake Valve Diameter:
Exhaust Valve Diameter:
Spring Diameter:
Recommended Spark Plug: Motorcraft AGSF-32C or equivalent. Bored for 1/2" head bolts.
Flo-Tek 203505 Small Block Ford Aluminum Cylinder Head
Flo-Tek 203505 Small Block Ford Aluminum Cylinder Head
Flo-Tek 203505 Small Block Ford Aluminum Cylinder Head

Click image to enlarge



Q & A

What's in the Box

You don't need to spend a fortune to get a top-performing, lightweight aluminum cylinder head for your small-block Ford V8. This Flo-Tek head has a long list of high-end features, minus the hefty price tag.

  • Head is sold individually
  • 180cc intake runners
  • 62cc exhaust runners
  • 1.94" intake and 1.54" swirl-polished exhaust valves
  • 58cc chambers
  • Performance valve springs (.550 lift)
  • 115 lbs. spring seat pressure
  • Compatible with most flat tappet camshafts
  • Hardened locks and retainers
  • PC seals
  • High-temp exhaust seats
  • Multi angle valve job
  • Bronze guides
  • 3/8" rocker studs and guide plates

See how this Flo-Tek head stacks up against the competition in Car Craft Magazine's tech article; 6 Small Block Ford Cylinder Heads That Work.

Head Flow Specs:

Lift        Intake        Exhaust
.400      209          137
.500      223          161
.600      248          191


  • Recommended Spark Plug:  AGSF-32C
  • Valve Spring Type:  Single w/ Damper
  • Valve Spring Application:  Hydraulic & Solid Flat Tappet 
  • Valve Spring Diameter:  1.465" O.D.
  • Valve Spring Seat PRessure:  115 lbs.
  • Valve Spring Rate:  280 lbs/in.
  • Intake Valve:  1.94"
  • Exhaust Valve:  1.54"
  • Valve Type:  Stainless, Swirl-Polished
  • Air Flow Data:
    • Intake
      • 223 CFM @ .500"
      • 248 CFM @ .600"
    •  Exhaust
      • 161 CFM @ .500"
      • 191 CFM @ .600"


  • These Flo-tek aluminum heads are the answer to the performance enthusiast and work on the small block Fords including the later EFI series when used in conjunction with an aftermarket intake, carb, and camshaft. Aluminum heads allow for a higher compression ratio than cast heads without creating pre-ignition problems. Check your piston usage with the 58cc combustion chamber for accurate ratio computation.
  • If using the heads on a 289 or 302 the upper row is 80 pounds net and the lower is 70 pounds. Torqued in stock sequence and increments. If using on the 351 with the larger bolts it is 100 pounds net torque in same sequence and increments as stock.
  • The head uses 3/8 rocker studs and requires the use of adjustable rocker arms like our part number: 91511772. You will need to check your push rod length to determine the correct length before ordering them.
  • Depending on the how much extra lift you are going to go with, you may also need different valve spring retainers that allow for more valve spring installed height.
  • We recommend using part #1011543601 with this head, this is an ARP head bolt kit.
  • These Flo-Tek aluminum heads for the small block Ford are specified to take plug number AGSF-32C


  • Recommended Spark Plug:  AGSF-32C
  • Valve Spring Type:  Single w/ Damper
  • Valve Spring Application:  Hydraulic & Solid Flat Tappet 
  • Valve Spring Diameter:  1.465" O.D.
  • Valve Spring Seat PRessure:  115 lbs.
  • Valve Spring Rate:  280 lbs/in.
  • Intake Valve:  1.94"
  • Exhaust Valve:  1.54"
  • Valve Type:  Stainless, Swirl-Polished
  • Air Flow Data:
    • Intake
      • 223 CFM @ .500"
      • 248 CFM @ .600"
    •  Exhaust
      • 161 CFM @ .500"
      • 191 CFM @ .600"

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910-11235 Instructions (PDF) 

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Main and Head Bolt Installation Instructions (Link)

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