Author Topic: 10 spline np203 input shaft  (Read 1395 times)

Offline 74ChevyK20

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10 spline np203 input shaft
« on: March 27, 2018, 12:25:22 AM »
Okay, so Iím a new member and this is my first post on the site. So my truck is, as my username suggests, a 1974 Chevy K20. The drivetrain is 350/465/203. I recently pulled the trans and transfer case to do the clutch and found the splines between the two to be almost stripped. I have access to another 465 with a good mainshaft, but Iím having a hard time finding a replacement 10 spline Input shaft for the np 203. Does anyone on here know where I can get one, or have one they do not need?

Offline Rapid Roy

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Re: 10 spline np203 input shaft
« Reply #1 on: March 27, 2018, 06:13:49 AM »
Welcome
1974 Cheyenne 10 LWB 350/TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Online ehjorten

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-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline 74ChevyK20

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Re: 10 spline np203 input shaft
« Reply #3 on: March 27, 2018, 11:39:18 PM »
Wow. If that ends up being the only place I will really need to think of speeding up my swap to a np205. That much money just for that shaft is outrageous.

Online ehjorten

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Re: 10 spline np203 input shaft
« Reply #4 on: March 28, 2018, 09:40:36 AM »
10 spline input gears for the NP203 have been discontinued for some time.  There is not an aftermarket source, so you have to find someone that has a used one.  You could convert your SM465 output and NP203 input to 32 spline.  You would probably spend about $600-$700 in doing so.  You could try contacting Randy's Ring and Pinion, Northwestfab, or any other some other drivetrain dealer to see if they have something laying around.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline blazer74

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Re: 10 spline np203 input shaft
« Reply #5 on: March 28, 2018, 06:12:06 PM »
203,s are still around and usually cheap due there not desired.

If your set on a 205 you will need the correct input shaft and adapter to mate the trans along with the driveshafts.
Being different lengths and your 74 should have the u bolt straps at the front T-case output  vs later years had a flange including the 205ís
A donor truck with everything is the best route if you can find one.

Squares are in the sights of  collectors now so everything is changing.

Offline 74ChevyK20

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Re: 10 spline np203 input shaft
« Reply #6 on: March 28, 2018, 10:53:07 PM »
My plan has always been to eventually put a 205 in it so I can do away with chain drive. And I am buying the trans from a friend, 465/205. I wanted to get the truck back together with the 203 because I didnít know how long it would be before he was pulling it out, today I found out it will be out soon though.

Offline Irish_Alley

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Re: 10 spline np203 input shaft
« Reply #7 on: March 30, 2018, 06:59:23 PM »
from my experience that setup should be upgraded if you plan on abusing your truck just a little. the 10 spline is weak (203 or 205) and the 1st gen yokes are another weak point where the nuts can back off and cause you to lose your front driveshaft leaving you without 4x4. even just upgrading that front yoke/output shaft is worth it but since you say your splines are damaged already then i would just replace the whole thing. if you can find a donor truck with the same wheel base and a sm465/205 then go for it. i was never able to break my trans output shaft even wheeling with 38s-44s so i wouldnt worry about a 32 spline output shaft unless you find one first or at a good price
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes