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Discussion Starter #1 (Edited)
I have seen the NP205 discussed numerous times. This guy (Austin Craigslist) is selling one for 300.00 and gives a pretty good over view of the NP 205. I have seen threads that have explained some of the same things but not collected like this one. (Could be that I have not explored enough) This ad caught my attention.

Here it is:


np205 transfer case
Bolt Pattern:

All GM NP205 cases 1971-1985 had a 8 bolt "racetrack" bolt pattern

All GM NP205 Cases 1986-up had a 6 bolt circular bolt pattern

Input Spline: GM Used four different input shaft configurations on these cases.

10 spline (from SM465 Applications): (1971-85) The most common were units supplied with a 4 speed which typically had a 10 spline male input shaft.



27 spline (from Turbo 350 applications): (1971-79) The units supplied with a T350 automatic have a 27 spline male input shaft.



32 spline SHORT (appx 2" stickout)

32 spl LONG a(appx 3-5/8" stickout)

These are both from (Turbo 400 applications) (also some SM465 86-up may have used a 32 spl input.) We have seen both a short (about 2.0" stickout) and long (3-5/8"" stickout) versions of this gear. The adapter casting in both cases is 4-3/8" long. With the short input, the trans will have an output shaft that sticks out of the main case of the trans appx 4" With the Long input, the trans will have a shorter mainshaft: Sticks out of the main case about 2.5"



Also see data on swapping input gears lower on this page.

1979 to 1985 GM NP205: 8 bolt "racetrack" bolt pattern:

During these years, the GM NP205 showed up behind Turbo 400 and SM465 Transmissions in 1 Ton trucks only.. 1/2 and 3/4 T trucks began to be supplied with the NP208 instead. SM465 units will still typically use the 10 spline input. Turbo 400 units have the stout 32 spline female input (in most cases the short 32 spl input, about 1.5-2.0" stickout) however still uses the 8 bolt "racetrack" bolt pattern.

1986 and Later GM NP205: 6 Bolt circular bolt pattern:
At this point GM updated the unit to use the same 6 bolt circular bolt pattern used on the NP208, and all subsequent GM full size 4x4 truck applications. All of them are the 32 spline female input, although those we have seen are the long (about 3.5" stickout) 32 spl input.

Front Output
GM used two front output shaft configurations, one had a spline count of 10, the other was a 30 spline. 10 splines came before 1977 (roughly) 30 spline shafts came after 1977 (again, roughly). One quick way to tell them apart is by the fact that 10 splines came with a 1310 series yoke output, capable of accepting a CV or yoke driveshaft. 30 spline shafts came with the flat flange on the output, capable of accepting the GM 3R series CV joint.

The 10 spline output will accept the stock 1310; Or a separately purchased 1330 or 1350 Spicer u-joint yoke, and the 1310 CV yoke. The 30 spline flange will accept the 1330 or 1350 CV joints.

Rear Output
The most popular version Is a 32 spline shaft / fixed yoke and will accept a 1310, 1330, or 1350 u-joint yoke, and the 1310 CV yoke.

Some were slip yoke, with a longer tailhousing.
 

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So, what's the question?
 

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Discussion Starter #3 (Edited)
I love the web site. Just trying to contribute. But I would love for someone to pick this apart. That's how I am going to learn.

Tim aka FATMAN

The ride: A tired old pickup that would benefit from a good 4bt. - Still dreaming of the day!
 

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Sorry, I misunderstood. I thought you had questions about the 205. No worries - as you were :beer:
 

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Fatman, you seem to know alot obout the NP205. The one I have is 1991 Dodge and it has 30 spline front output with the flat flange. What I want to do is connect this to my 1310 cv shaft for my 75 chevy k10? Is it better to change the output to 10 spline and use the 1310 yoke or will the later model chevy drive line bolt up to the dodge flange?
 

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205 question

If it were me using the tcase you have i would leave it alone. take your stock driveshaft and bolt it up and see. If it doesnt work just get the flange part of a dodge frond driveshaft and have a shop or yourself weld the dodge flange onto your chevy driveshaft. Or just take the dodge drive shaft and use that!
 

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np205

Thanks Jay, You have responded to both of my questions. I am stiil gathering parts and knowledge for this build, with this kinda help it will be easier!

Thanks:)
 

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Discussion Starter #9
From FATMAN:

Thanks Jay! Truthfully , I don't know squat about the np205. Just that it is gear driven (vs chain driven) and is a good choice for the 4bt conversions. As I have been told it is bullet proof. The post started with me coming across information from a seller on Craigslist. I posted his information. Now, the ego side of me would like to claim credit for the post information, but I would eventually steer someone in the wrong direction. I am a bigger man than that (remember FATMAN :) ). Just thought the information was valuable and wanted to run in a post to see what the real experts thought. By the way, it was nicely compiled and I salute the seller of the NP205 on Craigslist for that.
 

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Fatman, you seem to know alot obout the NP205. The one I have is 1991 Dodge and it has 30 spline front output with the flat flange. What I want to do is connect this to my 1310 cv shaft for my 75 chevy k10? Is it better to change the output to 10 spline and use the 1310 yoke or will the later model chevy drive line bolt up to the dodge flange?
1 dodge and ford both used 32 spl front and rear output
-recount it, if it does have 30 some one stole your 32.

If it were me using the tcase you have i would leave it alone. take your stock driveshaft and bolt it up and see. If it doesnt work just get the flange part of a dodge frond driveshaft and have a shop or yourself weld the dodge flange onto your chevy driveshaft. Or just take the dodge drive shaft and use that!
chevy used both yoke and flange style 30 spl cv yokes. if it realy does have a 30 he can just use grab a stock 30spl cv yoke off another 205, buy just a new 30spl yoke style, or a 32spl yoke style, they are all commonly available. but you will have to watch out for seal id changes between 10, 30, 32 spl yokes.
 

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yes, ford, dodge, and ih all had divorced.

idk what the ih used for a front output shaft, but all the input shafts are 32spl.

you could get 1310,1330, 1350 ujoints for all the output/inputs, and 1410 and 1480 are also avaiable through spicer.
 
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