Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Th400 interchangability

Discussion in 'The Garage' started by 6.2puller, Feb 18, 2007.

  1. 6.2puller

    6.2puller 1/2 ton status

    Joined:
    Jul 8, 2004
    Posts:
    569
    Likes Received:
    0
    Location:
    New England
    Ok I am tired of dinking around with this TH400 in the dead cold of winter. I found a replacement so I can fix this one in the summer or add it to the spare parts pile.
    The replacement is a B+M unit. The seller says it was built for his drag truck and ran great. Says it was built for a 700 HP input and he ran it behind a 396 pulling high 400s HP. It is a 32 spline output 2wd. Seller says it is the same 32 spline as a 4wd and I just have to unbolt the slip yoke and bolt on my adaptor. Can anyone confirm or expell this mith befor I drive 2 hrs to look at this thing.
    Thanks
     
  2. b454rat

    b454rat 1/2 ton status Premium Member

    Joined:
    Jan 21, 2003
    Posts:
    3,009
    Likes Received:
    7
    Location:
    Binghamton NY
    I think you will need a spacer to run this. Actually pretty sure you will. I have a 2wd 400 in my 89, and in order to run a Ford 205, I needed a 2" spacer with the proper Ford 6 bolt clocking, which is different than GMs. Now that I think about it, I used a 208/241 adaptor, so maybe with 400/205 adaptor you won't need it???
     
  3. 6.2puller

    6.2puller 1/2 ton status

    Joined:
    Jul 8, 2004
    Posts:
    569
    Likes Received:
    0
    Location:
    New England
    Anybody else know anything about this?
     
  4. darryl

    darryl Registered Member

    Joined:
    Jan 14, 2007
    Posts:
    33
    Likes Received:
    0
    Location:
    edmonton canada
    in 1979 to 1981 the th400 2wd worked with the 205 t/case
    i may be off 1 year either way though
    just get him to measure from the main case at the 6bolt adapter mount to end of shaft then compare to yours
    sorry for the instructions via lecture i am pretty grumpy tonight
     
  5. 6.2puller

    6.2puller 1/2 ton status

    Joined:
    Jul 8, 2004
    Posts:
    569
    Likes Received:
    0
    Location:
    New England
    Well for the record this one did not match up. I know have a broken tranny and a good one with the wrong output. I get to play operation tranny output swap. Sounds almost like a sex change or something :doah:
     
  6. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,540
    Likes Received:
    926
    Location:
    Massachussetts
    why..

    Why did GM use SO MANY different T-cases,trannys,and adapters???...:confused:

    You would think they would have made more things interchangeable (like all their engine parts,etc),rather than make a hundred diffrerent versions of everything!..goes against their "keep it simple" motto,IMO--..

    I was wondering if the '74 Monte Carlo TH400 I have sitting in my shed would bolt up to my NP208 that is already behind a TH400 in my '82 K20...looks like it would,but I haven't tried it..maybe I'll yank the tail off the Monte TH400 and see if my "spare" T-case and adapter fits it,in case I need it someday..my hopes are not high,with my luck I'll be "gutting" the old 4x4 tranny and swapping the output shaft..nothing like having a shed full of parts that don't fit and you cant use,huh?..:crazy:
     
  7. Speedo

    Speedo 1/2 ton status Premium Member

    Joined:
    Oct 31, 2005
    Posts:
    474
    Likes Received:
    27
    Location:
    Talkeetna, Alaska

Share This Page