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327 .60 over

Discussion in 'The Garage' started by shaun, Sep 23, 2003.

  1. shaun

    shaun 1/2 ton status

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    I have a 327 in my 71 blazer. I want to keep it and try it out which is why I amrebuilding it. BUT I just found out it is bored .30 over already. And have been told it will have to be bored again. What effect will it being bored .60 over have compared to it stock. Is this smart or will it make my engine to weak. Any help and over all suggestions. Thanks /forums/images/graemlins/1zhelp.gif
     
  2. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    might run into some cooling probs Why not bore it .040 over??? trw makes .040 flat tops for a 327 it should clean up at .040 if not .060 should be fine but like I said you may have cooling issues if you have a small radiator /forums/images/graemlins/truck.gif
     
  3. shaun

    shaun 1/2 ton status

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    It can be bored just .10 more over. This is the first engine I have ever built so I dont know. It will see some extreme trails though so I dont want it to weak?
     
  4. Beast388

    Beast388 1/2 ton status

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    You'd be lucky to be able to go to 0.040 over from 0.030. The difference is only 0.005 of cylinder wall, chances are that much material has already been worn off. I wasn't that lucky.

    My 388 is 0.060 over and I have had zero problems. The last 327 was produced in 1969 so the block should be a heavy casting. There should be plenty of material to go to 0.060 over. You can always have the cylinder walls sonically checked for thickness to be sure.

    Heck, you might as well toss in a 3.75" stroke crank and make it a 388! /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
     
  5. sled_dog

    sled_dog 1 ton status

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    a 327 isn't the greatest truck motor, can be nice of course but personally I'd put a 350 or 383 in my truck and save a 327 for a car or sell it to someone for a car. And don't 327s have different journal sizes than a 350 for a 383 crank to work?
     
  6. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    some do some don't crank and pistons are the only differance between them you could turn down a 350 crank to fit in a small journal 327 block I don't know if you could turn a 400 crank that far down
     
  7. Thumper

    Thumper 1/2 ton status

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    Well, I have a 327 bored .060 over for about 5 yrs now in mine. It does run warm, you need a good cooling system for it thats for sure. But as far as I ever was told, the bore size of a 327 is the same as a 350, just a different stroke... so a 350 .060 over is the same wall thickness as a 327 .060 over. *shrug* thats what I was told. Since its the same block.
    Anyways, I had the same issue. I had the motor in the truck, wanted to rebuild it, and they told me it was already .030 over, and it was worn .018 into that... so I had to go .060. The machine shop had no issues with doing it, but they warned me it would run hot, and they were right.

    Mike
     

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