Oil for 1979 rebuilt 350 w/high comp.heads

Discussion in 'Lawn Mowing' started by KBW, Apr 28, 2004.

  1. KBW

    KBW LawnSite Member
    Messages: 64

    Just bought a truck that has a rebuilt 350 in it. The guy I bought it from said he rebuilt the entire engine. He bored it out 30 over and put high compresion heads on it. What weight oil do you recommend? Reg/synthetic?


  2. kc2006

    kc2006 LawnSite Silver Member
    Messages: 2,443

    I normally run 20w50 in my race engine but 10w30 would be fine also. I tried it in my engine but it was too thin and didn't respond well to it. I run part synthetic in my race engine also, if the engine has any leaks now with regular oil then it will leak alot more with synthetic because the molecules are so much finer and more slippery it will leak more.
  3. dishboy

    dishboy LawnSite Fanatic
    from zone 6
    Messages: 6,177

    10w30 or straight 30 in summer. I like synthetics also. I would not go any higher than 30w most thinking now is that lighter oils lube better because they flow faster. Our new Ford 330 calls for 5w20. The Valveline rep said 10w30 was a better oil than their 10w40. Straight 30 is supposed to give better cylinder wear, but over synthetics, doubtful. I run 10w30 winter, 30w summer in my 350, 256k so somethings right.
  4. RTallday

    RTallday LawnSite Member
    Messages: 214

    Id run regular oil in it for a little while, maybe 2 oil changes to make sure its been broken in properly, then id switch to a synthetic. Mobil 1 15w50 is what i use in my truck. Its great.
  5. KBW

    KBW LawnSite Member
    Messages: 64

    Thanks for the advice.


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