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Big block question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 89Jimmy, May 19, 2003.

  1. 89Jimmy

    89Jimmy 1/2 ton status

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    Hello,
    Sorry if this is redundant, didn't find in a search. I need to repower my '85 K5. I've only considered a smallblock. However, I just found a 427 out of a moter home. I've a got a 700r4 in the truck. Will it stand up to a big block? Any flex plate or bellhousing issues? Are there any "bad" 427s that should be avoided? Thanks in advance.
    John
     
  2. SCOTTS_4X

    SCOTTS_4X 1/2 ton status

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    yeah it'll stand up to a bigblock, but the bigblock will know it down each and every time. a 400 should be behind a bigblock.

    -Scott
     
  3. morphed86k10

    morphed86k10 1/2 ton status

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    It probably won't blow up (the tranny), but it will die much sooner. On another note, are you sure its a 427 in the motorhome? I don't know much about them, but it seems to me the 427 is an odd choice for a motorhome.
     
  4. Sparky87k5

    Sparky87k5 1/2 ton status

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    Never heard of a motorhome that had the 427, unless it's been installed by a PO. That said, it's a bolt-in swap and well worth it. I love mine and find it much stronger then the previous smallblock. You'll need all new front brackets for PS, alt. and A/C compressor. If the 700 is built correctly, it'll hold up although it's not the best choice of trans. A T400 would be a better choice.
     
  5. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

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    Most GM Motorhomes were built with 454's from the mid to late 70's forward. 427's were dropped after '69 since the 454 came out in '70. Either you the motor home it was pulled from was really old or somebody swapped one in for a dead 454. 427 would be a wierd choice for a motorhome though.

    There is one 427 you want to steer away from. The tall deck 427 from the medium duty Chevy and GMC trucks. Its still a 427, but the tall deck requires a difference in many things from accesory brackets to the intake manifold. The best things people have done with the tall deck blocks is stroke the hell out of them and add a ton of cubes to it. That being said, if your plans are to just drop it in, I'd stay with a conventional big block and stay away from the tall deck. The swap would be much easier.
     

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