1971 LT1 Cylinder heads

Discussion in '1970 - 1973 Specific' started by Andrew Cabral, Aug 4, 2020.

  1. wnmech

    wnmech Veteran Member

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    Thanks jbloake for that info because that CEC1 does match the stamp on the back side of my block as the picture I posted earlier. That pretty much assures that my engine would of been replaced sometime in warranty. My door label said September 1970 car was made so probably sold sometime after that.
     
  2. COPO

    COPO Veteran Member Lifetime Gold Member

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    head_pad (3).JPG

    778420B5-055F-4DBA-85E1-5651C15DDAC2.jpeg
     
    Last edited: Aug 6, 2020
    jbloake likes this.
  3. jbloake

    jbloake Veteran Member

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    COPO’s posting, Interesting numbers if I am reading them correctly CE192345 , L30, December 3 1970 .From what I have been reading the 92345 was a continuation number for Flint when they used up all their numbers , hence December
     
    Last edited: Aug 10, 2020
  4. COPO

    COPO Veteran Member Lifetime Gold Member

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    I see L30 but what’s weird is that my car is a 05E. But remember, GM Experimental in Oshawa ordered the car for testing and maybe some thoughts about changes for 1971. So maybe they blew up the factory engine plus this car wasn’t intended to be sold.

    Month and day is 0522 on the protect-o-plate for the engine.
    Date of original retail sail is 6 17 70 in selling data portion written
    by hand plus a stamp from the dealer being Ontario Motor Sales Ltd etc.

    Muncie date on the protect-o-plate is P0E08.
     
    Last edited: Aug 10, 2020
  5. monzaracer

    monzaracer New Member

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    Ok as for me I LOVE 441/487/487X heads. Some of the easiest to get power from and not choke on most mid lift.550 down cams, plenty of meat to port.
    One trick is to get Kline guide liners installed then I set heads up in mill and raise the guide on port side 5/32 of an in with spotting tool then basic sand roll/carbide burr clean up under valves, do a 30° back cut on valves (use one piece stainless swirl polished) I also love installing flat guide plates and screw in studs in all of them and a quick cut for bigger springs round out machine work. Hogging really doesn't help, just give good port match and and smoothing clean up. Then decent intake and carb.
     

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