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Diesel TH400 Question...

Discussion in 'The Garage' started by botboy, Aug 7, 2006.

  1. botboy

    botboy 1/2 ton status

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    Okay guys, gotta couple of questions regarding diesel autos & my new sixpack...

    I've got a 6.5 Chevy motor that I'm getting from a friend, came out of a 94-95-ish Chevy P30 Cube van. 6.5, no turbo, MFI (no PMD problems!).

    I want to put this thing in my '80 Chevy C30 Scottsdale six pack. I also want to turbo the motor (eventually) and convert the sixpack to a 4x4.

    So what I was thinking is this - my Sixpack currently has no motor or transmission. A guy I bought some stuff from on craigslist offered me a working TH400/NP205 combo for cheap - maybe even able to trade for it. I know that the TH400 came behind a 6.2 in a lot of trucks and some 6.5's in later years. So...what I need to know to make this swap is the following:

    1) This 6.5 had an electronic transmission behind it, 4l60e or 4l80e or something along those lines. Is this flexplate going to fit up to the torque converter for anything besides the original trans? TH400 especially?

    2) Besides the torque converter, what other differences were there between a gasser TH400 and diesel TH400? I'm pretty sure the one being offered to me is from a gasser motor but the owner wasn't completely sure.

    3) Given the answers to #2, how hard are these items to find and swap over to a gasser transmission so it shifts correctly for the application?

    4) Any difference in the 4x4 trans/tranny x-members for sixpacks and blazers/K10's?

    5) The sixpack originally came with a 454/TH400 combo (2WD). Will the diesel fit in the 454 motor mounts? If not, will the van motor mounts work, or will 6.2 motor mounts work?

    THanks for the help guys. I'm hoping to be posting some progress pics in the near future
     
  2. dremu

    dremu Officious Thread Derailer Premium Member

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    As for #5, I believe that the 6.2 and 6.5's share the same mounting as the one is just the other bored out.

    For #3 I would imagine that the diesel would need a different torque converter (stall speed), and maybe the modulator tweaked for shift points.

    Crossmembers I *believe* are the same for any given year/tranny/t-case combo. My experience on my '74 was that I could just slide mine back and drill the frame for any changes I made; I don't know about newfangled trucks like your sixpack.

    I'm glad, btw, to find someone else who calls them that :D

    -- A
     
  3. u2slow

    u2slow 1/2 ton status

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    Crossmembers are unique to crewcabs & 1-tons because the frame is 2" taller.

    73-84 crossmembers are low-slung at fit the same years t-case adapter. 85-87 (91) crossmembers tuck up higher, along with the shorter adapter for those years.
     
  4. dremu

    dremu Officious Thread Derailer Premium Member

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    Dangit, I *knew* about the goofy frame, too. :doah: Thanks for the clarification.

    -- A
     
  5. sweetk30

    sweetk30 professional hooker Premium Member

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    tranny needs new desiel convertor and govenor setup. other than that will bolt up no problems basicly. might need to get the vac setup for the modulator on tranny. dont forget th400 needs gas pedel kickdown switch setup.
     
  6. botboy

    botboy 1/2 ton status

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    Hmm...:doah:

    Are the frames the same width?
    Could a guy take a blazer/K10 crossmember and either use longer bolts & spacers at the frame, or spacers between the crossmember and tranny mount? Anybody done this?
     
  7. 86Cucvbeater

    86Cucvbeater 1/2 ton status

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    I think the frames are the same width. We put a 73-84 crossmember on my 86 that i swapped an np205 and new style adapter(out of a 91 1 ton) into. Put about a 4-5in tall spacer between the adapter and crossmember with no problems. Had to do this because the new style th400-205 adapters are a lot shorter than the older ones like previously stated.
     

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