Another Compression ratio and build spec's thread

Discussion in 'Street/strip 400/430/455' started by 1969RIVI, Jan 25, 2022.

  1. 1969RIVI

    1969RIVI Well-Known Member

    Hey Larry, question for you is it possible to use stock GM .020" steel shim head gaskets coated with copper coating on the Edelbrock aluminum heads?
     
    Last edited: Jan 27, 2022
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I don't think so. Early block and iron heads, yes, but I don't think you can use them with the Edelbrock heads.
     
  3. 1969RIVI

    1969RIVI Well-Known Member

    I was doing some searching last night and came across alot of mixed emotions on weather it's ok to use them or not. Some guys say yes coat them and no issues, others no it's not a good idea at all. I think I'll go with the safe tried and tested route and order some cometics from TA. I have a bunch of gaskets including steel shims but nothing under .040.
     
  4. DaWildcat

    DaWildcat Platinum Level Contributor

    1969RIVI likes this.
  5. DaWildcat

    DaWildcat Platinum Level Contributor

    Ha! Great minds think alike, LOL

    Devon
     
    1969RIVI likes this.
  6. 1969RIVI

    1969RIVI Well-Known Member

    Devon, that's EXACTLY what the common consensus was in all the forums and threads I was reading up on.
     
    DaWildcat likes this.
  7. 1969RIVI

    1969RIVI Well-Known Member

    Larry, you mentioned your engine is at 10.5:1 and I assume that's like the perfect sweet spot for a street motor. Mine came out 10.32:1 on your calculator, is it worth while milling the heads down a bit to bring the combustion chamber cc's down from the advertised 68cc to a lower number, still using the .027 cometic gasket and raising the compression up to 10.5:1? Or is it not going to make any difference at all and is just money wasted?
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I would leave it at 10.32:1 Not worth the trouble IMO. It should run strong.
     
    1969RIVI likes this.
  9. DaWildcat

    DaWildcat Platinum Level Contributor

    x2.

    Devon
     
    1969RIVI likes this.
  10. 1969RIVI

    1969RIVI Well-Known Member

    I hear ya! It's just me over analyzing everything cause I want to get the build done right the first time:D. Thank for reeling me back in fellas!
     
    DaWildcat likes this.
  11. telriv

    telriv Founders Club Member

    Then you may have to deal with intake manifold alignment.

    Tom T.
     
    1969RIVI likes this.
  12. 1969RIVI

    1969RIVI Well-Known Member

    That is also very true Tom!
     
  13. mikegs400

    mikegs400 Well-Known Member

    I wonder what chevy was using in late 60s on the 375 horse big block alu. head ?
     
  14. sean Buick 76

    sean Buick 76 Buick Nut

    Even though it may not be a popular opinion to run steel shim gaskets with alum heads I’m sure it works fine in most cases.
     
    Schurkey likes this.

Share This Page