identify small block chevy cylinder heads 0303-0409-0504

Discussion in 'VIN, Trim Tag & Drivetrain Decoding' started by 67camaro400sbc, Jan 16, 2021.

  1. 67camaro400sbc

    67camaro400sbc New Member

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    i just purchased a pair of sbc aluminum cylinder heads,there is no name on them and the only numbers are 0303-0409-0504 and the other head 0303-0411-0250.When i bought them i was told they were from a 350 and 64cc and have 1.6 and 2.02 valves,but they had steam holes so i know they were on a 400 and i measured the cc and it measured to 68cc.The length of the valves are .100 longer then stock.The heads are going on a 400.They look like speedmaster heads because of the accessory holes,3 on one end(2 on top and 1 on bottom) and 3 on the other end(1 on top and 2 on bottom).I saw on other blogs that they were just generic heads no name but that doesnt help me,i would like to know the runner size and if they are matching set.i dont know if the steam holes were drilled afterwards.They had alot of carbon on the inside so i know they were used together.Iam planning on porting them and rebuilding them.Any help would be greatly appreciated.
     
  2. Chevyforever

    Chevyforever Veteran Member

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    Pictures would help ...
     
  3. 67camaro400sbc

    67camaro400sbc New Member

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    i dont have a picture of them but they look like a speedmaster PCE 281.2158 and they have the 4 mounting holes for the valve cover
     
  4. sandlapper

    sandlapper Veteran Member

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    Perhaps you ask ... speedmaster
     
  5. 67camaro400sbc

    67camaro400sbc New Member

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    i didnt even think about that,i will contact them tomarrow,thanks
     
  6. 67camaro400sbc

    67camaro400sbc New Member

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    i contacted speedmaster and they said that they dont sell heads with steam holes in them(that could of been drilled after it was purchased) but the part numbers dont match any of their numbers.The numbers i posted was not hand stamped numbers they were molded in the heads but they were hand stamp numbers and letters but they were unreadable they look like a A17U2
     
  7. sooner

    sooner Veteran Member Lifetime Gold Member

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    ^^This.

    I buy a bunch of aluminum chinese heads. There are 3 basic types of them right now.

    Which one looks like the ones that you have?


    Procomp.PNG


    upload_2021-2-2_15-42-38.png

    upload_2021-2-2_16-0-24.png
     
  8. 67camaro400sbc

    67camaro400sbc New Member

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    the third picture looks just like mine
     
  9. sooner

    sooner Veteran Member Lifetime Gold Member

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    Promaxx and flotek are using that style casting right now. If your heads are older heads, they might be Patriot heads.

    Promaxx bought out patriot some time back, but you might try contacting promaxx to see if those numbers ping on anything in their system.
     
  10. 67camaro400sbc

    67camaro400sbc New Member

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    i will contact them thank you
     

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