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305 or 350?

Discussion in 'The Garage' started by TwistedSkipper, May 29, 2006.

  1. TwistedSkipper

    TwistedSkipper Registered Member

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    I am trying to identify what size motor is in my '83. The sticker under the hood says its the 5.0, but it has aftermarket valve covers, a holley carb. I have heard different opinions from several people but I want to know whether to rebuild or buy a crate engine, (if it is the 305). It doesnt seem low on torque or power, just leaks and I want know for sure. Any suggestions?
     
  2. MattK

    MattK 1/2 ton status

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    check the block casting number. look straight down the firewall, on the driver side. facing upwards should be a 6-8 digit number. write it down and check out this site.

    http://www.mortec.com/castnum.htm
     
  3. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    I am willing to bet its a 305.

    They are known to be leaky
     
  4. shockline

    shockline Registered Member

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    If it is gutless and leaks then its a 305, my 84 came with one from the factory. I tried to pull a boat up a mountain and could not get above 10 mph with it.
    If it is the originial then the engine code on the vin will work.
     
  5. scrappyk5

    scrappyk5 1/2 ton status

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    not to change the subject , but i have a 305 in my 1984 that came from a
    1987 truck and it seems to be pretty good on power and it doesnt leak. :D
    i know the it was a tbi motor in 1987 but when the p.o. stuck it in my blazer, he put the carb and exhaust that came with the blazer. maybe that changes the power level.
     
  6. slicer4559

    slicer4559 Registered Member

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    all 305's are good for only 1 thing, "boat anchors", best bet is to get a crate motor 350ci. or in my case, i have a small block 400. cya.
     
  7. beater_k20

    beater_k20 Banned

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    all small blocks are known to be leaky after 24 years of service, especially if not well maintained.

    well, obviously you havent had a good 305. most likely, you have only owned or driven a few 305s. i have owned a couple of them. one was a 1993 C1500 (exact same longblock as the 87, shortblock dates back to 1986) it had around 220K on it when the trans died for the second time, and i traded it off. in that 220K it had never once had the valve covers pulled off. didnt leak a drop, didnt burn a drop. the other was in an 86 C10. had the valve cover gaskets replaced in '92, and that was it. 114K on that one, and i pulled it, stabbed a little bigger cam in it and drove it for a while. it has since been retired to demolition derby use. its been through 6 derbies with both myself and friends behind the wheel. never once has it let us down, despite being past 250* a couple times.

    400s are boat anchors too, due to their cooling problems.
     
  8. slicer4559

    slicer4559 Registered Member

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    beater k20, then you are one of the fortunate few...lol, i've had too many friends with the 305's that were nothin but problems, but you already know that you look around enoughyou'll find bad crap even in brand new trucks. have a good one, beater. cya,
    Brian
     
  9. SchnorrCS

    SchnorrCS 1/2 ton status

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    I had a 305 in an 83 1/2 ton. Decent power, 183,000 miles, only place it leaked was my own dumb ass faul, dropped the valve covers off the work bench, didn't notice they bent at the edge, put em back on, and for the life of me couldn't figure out why it wouldn't seal...haha
     
  10. readymix

    readymix 3/4 ton status

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    My 305 has almost 230Kmi on it right now, and yes it leaks like a siv, but I would not say it is gutless
     

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