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.

Np205-Th350

Discussion in 'The Garage' started by adamforsythe, Aug 24, 2005.

  1. adamforsythe

    adamforsythe 1/2 ton status

    Joined:
    Oct 16, 2004
    Posts:
    1,394
    Likes Received:
    0
    Location:
    Maine
    Hello,
    I know to mate up a Th350 and a Np205 I need to shortin the tail shaft. How would I go by doing this? Do I have to drop the tranny and rip all the gears out to get to the tail shaft? When I had the tranny out I really did not look at the tail shaft. So I don't know if I can remove it from the back. I really don't want to take the truck to the shop because I want to say I built the truck up 100% myself and with the help of a few friends. :D Plus not taking the truck to the shop will save me MAD $$$$$$$$$$$$. :bow: :D :D :D
    Thanks
    Adam
     
  2. 1979jimmy350

    1979jimmy350 1/2 ton status

    Joined:
    Mar 24, 2004
    Posts:
    3,069
    Likes Received:
    0
    Location:
    Ann Arbor Mi
    the 350 tranny with the right adapter will bolt right up. If you mean the 700r4 you can just get a spacer or you can put in a special output shaft which is about $150 from advanced adapters
     
  3. clarkjw24

    clarkjw24 1/2 ton status GMOTM Winner

    Joined:
    Dec 4, 2003
    Posts:
    3,531
    Likes Received:
    2
    Location:
    McBee, SC 29101
    Th350s came with NP205s. I'm not sure what your asking. If you've got a th350 adaptor, coupler, and a 27 spline NP205 its direct bolt in. ?????
     
  4. wazzabie

    wazzabie 1/2 ton status Premium Member

    Joined:
    Apr 17, 2001
    Posts:
    1,719
    Likes Received:
    5
    Location:
    Washington State
    I found a NP205 mated to a TH350 from a 72 K5 and it fit perfectly with my TH350 on the 78 K5. I did not need to tear into my tranny. Be sure to put new seals in the adapter cause I think a bad seal could get t-case gear fluid into the tranny. Some do not run gear oil in the t-case for this reason. I was able to pull all the parts from a 72 K5 with low millage for onlt $250 bucks. Only two problems. I had to bend the shift linkage. The rail mount from the 72 K5 was to short for the 78. Maybe someone knows how to fix this.
     
  5. adamforsythe

    adamforsythe 1/2 ton status

    Joined:
    Oct 16, 2004
    Posts:
    1,394
    Likes Received:
    0
    Location:
    Maine
    Hello,
    Right now I have a Np208 mated with my TH350 and I thought to bolt on a NP205 the tailshaft has to be shorter.
    Am I wrong?
    Thanks
    Adam
     
  6. wazzabie

    wazzabie 1/2 ton status Premium Member

    Joined:
    Apr 17, 2001
    Posts:
    1,719
    Likes Received:
    5
    Location:
    Washington State
    stock I had a np203 to the th350. Maybe some experts can chime in or the answer could be found searching the forum.
     
  7. bigjbear

    bigjbear 1 ton status Staff Member Moderator

    Joined:
    Feb 18, 2000
    Posts:
    13,970
    Likes Received:
    450
    Location:
    Marietta GA
    From the research I've done in the past 2 weeks I think you are wrong. You will need the TH350/NP205 adapter and a 27 spline coupler. This assumes the NP205 you have came from behind a TH350.

    BTW, if you do go ahead w/ the swap I'm in the market for a TH350/NP208 adaptor. Let me know if you are intrested in selling it.
     
  8. 1979jimmy350

    1979jimmy350 1/2 ton status

    Joined:
    Mar 24, 2004
    Posts:
    3,069
    Likes Received:
    0
    Location:
    Ann Arbor Mi
    i do think you are going to have to do some mods if you had a 208 behind a 350 tranny. You can go two different ways you could get an output shaft from a older 350 trany and swap it in or you could get a spacer so you do not have to tear the tranny down or even take the tranny out of the truck.
     

Share This Page