Any ideas on this 340 block ?

Small Block Mopar Engine

  1. 72SwingerJosh

    72SwingerJosh Well-Known Member

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    I found this ad for a 340 block on market place and it has me a little puzzled. It has a cast date for the year 1978. The block looks pretty rough and I’m not sure it would clean up or not. Anyone have any ideas about it? Here are the ads pictures, I cut and pasted them to here.
    4F39E390-56F3-4724-A644-51569A638442.jpeg EDCF7302-7448-4544-9A3D-557427F8F9B2.jpeg 2BD5A350-17DC-4DFC-94E5-22FBE6444AF6.jpeg BE8463A4-7ADA-4E89-8EA1-7C9512C2D381.jpeg D87CE085-AC7C-419E-A0F7-5F430DBC0F9B.jpeg D81BAA8F-F198-4493-8031-3385A8E40942.jpeg
     
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    • Rat Bastid

      Rat Bastid Dunamis Metron

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      It’s possible it was an over the counter replacement block but that is just a wild guess. Other than that, I can’t even come close to explain it.
       
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      • toolmanmike

        toolmanmike Moderator Staff Member FABO Gold Member

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        It's probably a 73. The date is all rusted up in that area.
         
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        • Rat Bastid

          Rat Bastid Dunamis Metron

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          Well that certainly makes more sense. I should have put my glasses on while looking at the pictures.
           
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          • memike

            memike Super Moderator Staff Member FABO Gold Member

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            You beat me to it Mike, yes !! That is a 73 block
             
            Last edited: Jan 21, 2022
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            • Garrett Ellison

              Garrett Ellison Amateur driver on public roadway, do not imitate.. FABO Gold Member

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              Yep, ‘73 block. Just curious, what are they asking for it?
               
            • A56

              A56 MoPar Affliction FABO Gold Member

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              I looked at that last week. Def. a 73 'but won't ship from Mo.
               
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              • 72SwingerJosh

                72SwingerJosh Well-Known Member

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                Thanks that makes sense now. I think it looks like it would need quite a bit of work.
                 
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                • memike

                  memike Super Moderator Staff Member FABO Gold Member

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                  I wonder how much will have to be taken off the head surface and cylinders..?
                   
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                  • Demonracer

                    Demonracer 71 Demon 00 Ram 16 Chrysler 300S 05 Caravan FABO Gold Member

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                    Being as it's a 73 cast date & it's measuring 4.060 on the bore, it needs to be checked over by a good machinist & then sonic tested to see if it will clean up at 4.070 or 4.080.
                     
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                    • memike

                      memike Super Moderator Staff Member FABO Gold Member

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                      I do agree, 400 dollars for that 73 340 block as it sets, seems very pricey for a block in that shape, could be a boat anker...
                       
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                      • MOPAROFFICIAL

                        MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                        $400.00 Anchor
                         
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                        • gzig5

                          gzig5 Well-Known Member

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                          If you want/need a 340 block there is a vendor (Mega Parts) out of NW Wisconsin that have several 340 blocks on listed on various sites including FB Marketplace. They seem to be in better condition for similar money. Mega Parts has a website too with a lot of mopar restoration parts. I would think that they'd be willing to ship since it is a pretty good size business.
                           
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                          • Garrett Ellison

                            Garrett Ellison Amateur driver on public roadway, do not imitate.. FABO Gold Member

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                            Whenever there’s that much rust, it’s rare to see one clean up at less than .040 over to get past the pitting.
                             
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                            • cudavert

                              cudavert DARTAHOLIC

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                              image_6948b572-732a-4264-9b5d-51bad2652640_1024x1024.jpg
                               
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                              • gzig5

                                gzig5 Well-Known Member

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                                I have a 273 block that would be a perfect candidate for a table base. That's pretty sharp.
                                 
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                                • Demonracer

                                  Demonracer 71 Demon 00 Ram 16 Chrysler 300S 05 Caravan FABO Gold Member

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                                  Depending on the OP's location, there may be better candidates available.
                                   
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                                  • Dartnut

                                    Dartnut Don't hate me because i'm beautiful

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                                    I wouldn't pay $400 for that gamble.
                                    If you found a non rusted standard bore block that passed a magnaflux and sonic test for $1,000 you would be money ahead in the long run if you must have a 340.
                                    Good luck, and let us know how this turn out.....
                                     
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                                    • Oldmanmopar

                                      Oldmanmopar Going left turning right FABO Gold Member

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                                      I have some
                                       
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                                      • GTX JOHN

                                        GTX JOHN FABO Gold Member FABO Gold Member

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                                        I would not fool with that block.
                                        Rough as a Corn Cob!!
                                        You can find a decent one for a little more.
                                         
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                                        • MOPAROFFICIAL

                                          MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                                          If some of you don't mind 8 sleeves I know where there's a sleeve to standard 340 block all machined and squared up and they want $1,000 for it
                                           
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                                          • gzig5

                                            gzig5 Well-Known Member

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                                            @tinman2 I'm curious why you disagreed? I've purchased small parts from them in the past with no issues.
                                             
                                          • dustertogo

                                            dustertogo Well-Known Member

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                                            Not worth it IMO. I don't think a machine shop would give you very good news after checking it out.
                                             
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                                            • 604B1duster

                                              604B1duster Well-Known Member

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                                              I wonder when they stopped casting them ? Would 2-7-73 be a late casting ?
                                              maybe one of the last ?
                                               
                                              Last edited: Jan 21, 2022
                                            • 33IMP

                                              33IMP Well-Known Member

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                                              55 gallon trash can, a couple gallons of molasses, and offer two hundred.
                                               
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