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Chevy tranny th350 or th400

Discussion in 'Truck & Equipment Repair' started by kdm004, Mar 5, 2015.

  1. kdm004

    kdm004 Junior Member
    Messages: 2

    Hi there My plow truck just had its tranny go out/ no reverse on it I have a 1990 Chevy short box 4x4 with a 350 engine and a rebuilt TH350 tranny , I was wanting to know what is a better tranny to put in it . Do I have my TH350 rebuilt with HD kit or do I swap it out and put in a TH400 and matching transfer case . what is the opinion on both . Thanks for your time
     
  2. jhenderson9196

    jhenderson9196 Senior Member
    Messages: 615

    The 400 is a bigger stronger tranny. What gear are you running and what tire size. A tall gear and /or a tall tire are a working trucks enemy.How about plowing in low range? The 350 will hold up if you keep it cool and use low range in the heavy stuff.
     
    Last edited: Mar 5, 2015
  3. BUFF

    BUFF PlowSite Fanatic
    from FR NoCo
    Messages: 7,236

    400 is a tougher trans but a 350 is no slouch either when built. You may have to adjust drive lengths to go to a 400 but I not completely sure about it. Everything else should be a easy change over.
     
  4. JDosch

    JDosch Senior Member
    from Joliet
    Messages: 127

    I'd say 400 turbo.
     
  5. Plowtoy

    Plowtoy Senior Member
    Messages: 929

    Either built correctly are pretty strong. Its a 90, are you sure its not a 700R4/4l60? I thought the 350s and 400s went away when the old (80's) body style went away
     
    Last edited: Mar 6, 2015
  6. BUFF

    BUFF PlowSite Fanatic
    from FR NoCo
    Messages: 7,236

    Good catch, my 86 K-5 has 700R4 which I had built heavier for plowing. I looked at going to a 350or400 and found I needed to replace drive shafts.
     
  7. snoboss

    snoboss Member
    Messages: 57

    turbo 400s have failed miserably 15 to1 for a turbo 350 failure. sun gears,thru shaft, clutches, ect. jmo