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Tranny Swap

Discussion in 'Chevy Trucks' started by 73K20, Jun 18, 2003.

  1. 73K20

    73K20 Junior Member
    from PA
    Messages: 3

    Does anyone know of an acceptable replacment tranny to swap into place in my K20. It has the four speed with the creeper gear, and I am looking to put a five speed with OD that will bolt up to the New Process TCase and require the least amount of mods. Any Thoughts?
     
  2. Chuck Smith

    Chuck Smith 2000 Club Member
    from NJ
    Messages: 2,317

    Well, since you have the 4 speed with granny gear, your rear drive shaft has the center support bearing. You won't need that with any auto trans. So no matter what you will need a new rear driveshaft.

    The easiest swap would be to get a TH700 trans, mated to a NP 208 transfer case, with the front and rear driveshafts, and swap it in.

    Check at www.advanceadapters.com and see what adapters they have to use your NP205 transfer case with the TH 700, or 4L80E or 4L60E transmission.

    ~Chuck
     
  3. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    You definatly would lose alot of beef by going to a 700r4

    sm456 is a good stout trany. Almost indestructable. You say a k20 so do you have a 205 case?

    What are you doing that you want/need OD for? Do you care if you stay with a manual or is an auto swap ok? Usage will dictate which way you should go.
     
  4. wyldman

    wyldman Member
    Messages: 3,265

    He should have a 205 case,all 73's did.

    Like Chuck said,the 700R4 swap would is a good option,it's a direct bolt in,with the newer case and drivshafts.You would also need an automatic column,or use an aftermarket floor shifter.A donor truck would be nice,as you could just swap everything over.It was a very popular combo,and there are lots of them around.

    The 700R4 has lots of beef,and there are tons of aftermarket stuff to do them up right.

    You may be able to find a 700R4\NP205 stock combo in a newer 1 ton.

    You can also get an adapter to mate your 205 to a 700R4,if you want to go auto,or an NV 4500,5 speed OD manual.

    If you want to stay manual,then get a NV4500,and an adapter to bolt to your 205.You will need to fab a hydraulic clutch setup,or get a special belhousing with the mounts for a manual clutch linkage.If you can fab up a hydraulic setup,the clutch will feel a lot nicer.You will also need some driveshaft work to make it fit.
     
  5. 73K20

    73K20 Junior Member
    from PA
    Messages: 3

    Thanks Guys since I want to stay with the Manual it looks like time to go hunting an NV4500!!
     
  6. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    The NV4500 is the ticket.BUT it would be cool to swap in an NV5600 out of a Dodge/Cummins:cool: . If you tow heavy,and need tighter gear spacing,it would be useful.I think the cool factor of having a 6 speed HD manual in an older truck is the biggest sellling factor:D . The 4500 should be more than enough though.,and they are cheaper although not nearly as strong as the 5600.