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.

mating a SM465 to a np205/203 doubler

Discussion in 'The Garage' started by MountainJeeep, Jan 8, 2006.

  1. MountainJeeep

    MountainJeeep Registered Member

    Joined:
    Jan 5, 2006
    Posts:
    12
    Likes Received:
    0
    Location:
    Centennial, CO
    is this as easy as bolting it all up? or in my newbness, am I missing something critical? :o
     
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,188
    Likes Received:
    1,396
    Location:
    E-town baby!
    Need a SM465 to NP203 adaptor and ther correct 10 spline input gear for the NP203. Then it'll all bolt up. Of course you'll also need a doubler kit from NWF, WMS, or whoever else you might choose.

    Rene
     
  3. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    if you use a 10 spline 203. Could get a 27 spline output shaft from NWF and run that with a TH350 203. If I ever get tired of the slushbox this is the route I will take.
     
  4. u2slow

    u2slow 1/2 ton status

    Joined:
    May 9, 2001
    Posts:
    2,217
    Likes Received:
    0
    Location:
    BC Canada
    You can do a little more work for better strength...

    You can use an 81+ SM465 from a NP208/241 application. Add to that a 32-spline NP203 (Th400 type). The extra work is drilling/tapping the 6-bolt pattern on the face of the NP203.
     
  5. MountainJeeep

    MountainJeeep Registered Member

    Joined:
    Jan 5, 2006
    Posts:
    12
    Likes Received:
    0
    Location:
    Centennial, CO
    Thanks guys. This Chevy stuff is all new to me. Basically what I want to do is run a 4:1 doubler behind the 465 which will be mated to an 87-91' 350.

    That way I can take full advantage of the 6.??:1 gear ratio that the 465 has and still be able to slip from 4:1 to 2;1 as necessary. Also gonna triple stick it for as much versatility as possible.

    Now for a follow-on question. I plan on usin this rig to drive to trails and also be able to handle the toughest Colorado has to offer (indy, Buena carnage, and Billings), so will 4.10 gears in the diffs be a good choice or should I drop down further to the 4.56-4.88 range? i dont want to lose to much I-70 mountain climbing ability. Think Floyd Hill at a minimum of 65 mph with a fully loaded rig :-)

    Bill
     
  6. sweetk30

    sweetk30 professional hooker Premium Member

    Joined:
    Nov 1, 2004
    Posts:
    25,554
    Likes Received:
    548
    Location:
    horseheads , ny 14845
    we need lots more info on your rig to tell you what gears are needed. give use the specs.:o
     
  7. 6.2puller

    6.2puller 1/2 ton status

    Joined:
    Jul 8, 2004
    Posts:
    569
    Likes Received:
    0
    Location:
    New England
    I have a SM420/203/205 in my rig with 5.13s and it is not streetable even with the 39.5. Basically the 4 speed becomes a 2speed high or low. :eek1:

    I am currently building another heep for my wife and it will be 350,465,203,205 with 4.10s and 36s. Her rig will remain streetable but still be able to hang along with me and the guys if needed.

    You may be able to swing 4.56s or 4.88s if you are going with a 38" tire or so but with 35-36s you wont want it that tall. You can always throw the 203 in low if you need some umph. :D
     
  8. u2slow

    u2slow 1/2 ton status

    Joined:
    May 9, 2001
    Posts:
    2,217
    Likes Received:
    0
    Location:
    BC Canada
    I found 4.10s were too short for highway travel with the 465 trans & 33's. 3000+rpm all the time. :(

    You'd probably be okay up to 38s with those gears so long as you had the 203/205 combo.
     
  9. MountainJeeep

    MountainJeeep Registered Member

    Joined:
    Jan 5, 2006
    Posts:
    12
    Likes Received:
    0
    Location:
    Centennial, CO
    Gonna roll with 37-40" tires depending on what deals I can swing.

    ok, for those who missed my earlier post.... to rehash the plan for my build here you all go

    1987-1991 Suburban with a 350. I doubt I can score a 454 for my purchase price of no more than $1,000

    37-40 inch tires

    dana 60 front with detroit

    14b rear with detroit

    crossover steering

    hydro assist

    4-6" spings (havent decided yet) from either tuff country or BDS

    sm465 tranny

    205/203 triple sticked doubler for 4:1

    I will either exocage the rig or build the cage on the inside. i am leaning toward exo to attempt to preserve the body for as long as possible.

    Thanks all,

    Bill
     
  10. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,188
    Likes Received:
    1,396
    Location:
    E-town baby!
    That'd be OK in a Sub, but for most K5's that would be a brutally long combo. The 32 spline 465's had a pretty long output and adaptor...

    Rene
     
  11. u2slow

    u2slow 1/2 ton status

    Joined:
    May 9, 2001
    Posts:
    2,217
    Likes Received:
    0
    Location:
    BC Canada
    Good catch.. it is longer. The later 465/208(241) adapter is ~8" long. From pics, the 465/203 adapter looks like ~4"?


    [​IMG]

    [​IMG]
     
  12. MountainJeeep

    MountainJeeep Registered Member

    Joined:
    Jan 5, 2006
    Posts:
    12
    Likes Received:
    0
    Location:
    Centennial, CO
    U2Slow...you have a write up for that?

    thanks

    Bill
     
  13. u2slow

    u2slow 1/2 ton status

    Joined:
    May 9, 2001
    Posts:
    2,217
    Likes Received:
    0
    Location:
    BC Canada
    Sorry, no.... I've studied the parts in great detail though! :o
    Its the same modification to put an NV4500 and 203 together. Just pretend the 465 with the 208/241 adapter is an NV4500 ;)

    http://www.coloradok5.com/forums/showthread.php?t=127434

     

Share This Page