Cracked 350 heads

Discussion in 'Small Block Tech' started by UNDERDOG350, Jan 19, 2020.

  1. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    In another thread Sean mentioned 68-72 were found with cracks more so than newer heads.

    Sean, where were the cracks located? Do you have any photos? I'm dropping a set of 69 heads off at the shop for cleaning and Mag and would like to direct them where they would likely find cracks.

    Thanks
     
    Fox's Den likes this.
  2. sean Buick 76

    sean Buick 76 Buick Nut

    Look for cracks between the exhaust ports, sorry I don’t have pics. Normally between the center ports.
     
  3. Mart

    Mart Gold level member

    Oh oh, no pics no book!....:D:D
    :D
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

  5. BUQUICK

    BUQUICK I'm your huckleberry.

    I don’t have pictures but I had a set of ‘68 350 heads checked and they were both cracked under the valve cover.
     
  6. mikethegoon

    mikethegoon Well-Known Member

    Cracked alongside the springs - usually appearing as a gooey vertical line on what would be a normally clean surface. That stands for the 350/ 400/ 430. We just had a 68 430 come in the shop At my request the VC was pulled before anything was done. I was shocked to see the top of the head so clean. Low mileage -frequent oil changes. Yet the magnet picked it up. I. My estimate is the 68 v8 lasted about 30 thousand miles
     
    BUQUICK likes this.
  7. jay3000

    jay3000 RIP 1-16-21

    That's where the heads are??
     
  8. sean Buick 76

    sean Buick 76 Buick Nut

    I think you meant to quote me?

    yes the heads you sold me went to my turbo brother who posted above. I hate selling stuff but they went to a good cause.
     
    BUQUICK likes this.
  9. BrunoD

    BrunoD Looking for Fast Eddie

    I have a set of 70 heads out of a 70 GS350.Are they good heads?I will be selling them,as the car needs way too much work for a guy my age.Bruno.
     
    mikethegoon likes this.
  10. MrSony

    MrSony Well-Known Member

    About as good as any 68-74ish head flow wise.
     
  11. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    So I had a pair of 69 heads cleaned and checked. They magged them and found cracks in both. Then pressure tested and found bubbles. I pressure checked one for photos.

    120.JPG 118.JPG 117.JPG


    Is this where you have found cracks in the past?

    115.JPG
     
    PGSS and mikethegoon like this.
  12. mikethegoon

    mikethegoon Well-Known Member

    My current daily driver has a steam coming from inside driver side valve cover.Visible while running+ filler cap removed. I've been doing this too long to believe anything less than cracked head. Condensation etc. Although I have couple more sets68- 72. I'm thru with the drama.
     
  13. mikethegoon

    mikethegoon Well-Known Member

    That said I have an LT-1 on engine stand. If the salt doesn't destroy the frame that is. Heat and poor cooling will just about destroy any engine out of Detroit But Chevy is well served by the aftermarket. All you have to do is grab top half off 71-72 sbb. Heads rockers pushrods And don't look back.
     

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