Torque to yield bolts

Discussion in 'Engine Topic' started by Layne02, Aug 12, 2018.

  1. Layne02

    Layne02 Member

    95
    1
    Jun 25, 2013
    Georgia
    Hi everyone, building a 350 for my 80 Z28. Picked up some new head bolts and read somewhere they are torque to yield bolts and install differently than regular head bolts. Now I believe I put these same style bolts in my 73 few years ago without knowing the were the TYY bolts. Anybody know anything about this?
     
  2. Chevyforever

    Chevyforever Veteran Member

    124
    17
    Jan 4, 2011
    ontario
    Not sure what head bolts you bought, however TTY bolts are not req'd for a rebuild on that 350 block.
     
  3. Layne02

    Layne02 Member

    95
    1
    Jun 25, 2013
    Georgia
    Oh sorry, they are Felpro. Gottem at Advance. This isnt race motor or anything, just around town driving. I guess what I am asking is, if I used them in my 73 with a 350 and havent had a problem yet and I torqued like reg specs of standard bolts, what is big difference in them?
     
  4. Chevyforever

    Chevyforever Veteran Member

    124
    17
    Jan 4, 2011
    ontario
    Simply stated they are designed to be used once then discarded. To achieve proper torque they actually have to stretch a certain amount. If it was me I would return them and get a regular set of good old SBC bolts. Surely Fel Pro offers them. (ES72856) You need two sets for 1 engine.
     
  5. Layne02

    Layne02 Member

    95
    1
    Jun 25, 2013
    Georgia
    Ok see thats what I have and when I looked up an instruction sheet on them it says they are TTY, but then other places like Summit, it says they are stock replacement. Even on reviews some are saying they are TTY. Anyway, I put heads on last night and just torques them using normal torque values. We will see, thanks
     

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