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Any visual difference between 305 & 350

Discussion in '40- & 55-Series Tech' started by 74cruzah, Jan 17, 2003.

  1. 74cruzah

    74cruzah

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    Pulled the motor out of a 79 Chevy 2wd. Not sure if it is a 305 or 350. Does anyone know an easy way to tell? Getting it ready to rebuild and stick in the cruiser. Thanks.
     
  2. Gumby

    Gumby Supamod Staff Member s-Moderator

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    There are two numbers. One tells some info the other tells all the info. The casting number is cast into the side of the block. I have seen that number not tell you the final displacement of the motor though. The stamped number that lives on a protrusion on the right (passenger's) front just below the head will tell you everything. With those two numbers you can tell the displacement, day, week, year and shift it was made, the type of car it was installed in, the h.p. range and the transmission. There are a number of web sites that have this info, but there is one outstanding one. I'll google it and get back with it. It's a link Woody oughtta have if he doesn't already.

    AFAIK, there is no other sure way to tell besides measuring the bore or stroke.
     
  3. Gumby

    Gumby Supamod Staff Member s-Moderator

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    http://www.mortec.com/

    I was wrong. It looks like you can get displacement for sure just from the casting number. Still it's fun to get the other info from the assembly number as well.
     
  4. 74cruzah

    74cruzah

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    Thanks man, I will check it out.
     
  5. Niner

    Niner

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    I thought that the harmonic was thicker on a 305.

    I could be wrong.

    someone know?
     
  6. chevyboy69

    chevyboy69

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    an easy way to tell the difference between the 305 and 350 is if you look at the push rods the 305 have 6 inch push rods and the 350 have 8 inch push rods if i remember right all i know is the 305 push rods are shorter than 350 push rods
     
  7. handcannon

    handcannon

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    Gumby, I can't get the link to work.

    Don
     
  8. srgould41

    srgould41

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    I used Google to search for "Chevy small block casting numbers" and found more than 44k results.

    From one of the sites:
    "The Engine Block Casting code is one of the best ways to identify a Chevy engine block. This Casting number is usually found at the rear of the block on the left or drivers side on top of the bellhousing flange. "

    My 305 has a "5.0" cast into this location.

    You can also search on the exact casting code that you find there if unsure.
     
  9. zebrabeefj40

    zebrabeefj40

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    This would be complete BS... There's no way in he!! there is a 2 INCH difference in a SBC pushrod.

    Nick
     
  10. srgould41

    srgould41

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    I agree with Nick. The 350 and 305 have the same 3.48" stroke.


    Besides, who would want to tear down an engine to figure out the displacement? Just read the casting number :)