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28 spline axels?

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Old May 15, 2008 | 06:50 PM
  #1  
7375highboy's Avatar
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From: altoona
28 spline axels?

I have a 79 f150 2wd,that has a 450 hp 351c in it. I need to put better gears in it and I have a set of 389,s and a posi 28 spline. The only problems is my axels in my truck are 31 spline. Did ford put 28 spline axels in these trucks? If so I need a set.


thanks Jesse
 
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Old May 15, 2008 | 07:00 PM
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77Explorer's Avatar
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If you have 31 spline axles use them!

I just broke a 28 spline unit behind my 351W been outside in this rainstorm pulling my poor 9" apart.
 
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Old May 15, 2008 | 07:16 PM
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28 spline count

I have 28 count on mine, from the factory. 79
 
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Old May 15, 2008 | 09:24 PM
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Originally Posted by 77Explorer
If you have 31 spline axles use them!

I just broke a 28 spline unit behind my 351W been outside in this rainstorm pulling my poor 9" apart.
my axle..


 
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Old May 15, 2008 | 09:36 PM
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28 or 31 spline axleshafts.

1973/79 F100's / 1975/79 150's came both ways, it depended on the application.
 
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Old May 16, 2008 | 12:05 PM
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As others have said - 28 & 31 were available, but you will definitely want to go with the 31s!
 
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Old May 16, 2008 | 04:57 PM
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With that kind of HP stay away from the 28 spline, I twisted a set of 28 off with a stock 429, changed to the 31's and it never came apart again.,
 
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Old May 16, 2008 | 05:00 PM
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In my experience the 28 spline only came in the 2wd. very rarely did they have 32. But every 4wd ive worked on was a factory 32 spline.
 
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Old May 16, 2008 | 05:37 PM
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Yeah. I only thought 4x4's had the 31 spline.
 
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Old May 16, 2008 | 05:40 PM
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From: altoona
my truck have 31 spline and it is a 79 2wd.
 
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Old May 17, 2008 | 08:29 AM
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I've had nothing but 2wd's and several rear gear changes over the years and have found both 28 and 31 spline axles. Not sure but the 31 may be part of the 150 HD with the 6050 GVW. I know my truck has the factory power train with a 3.50 LS 31 spline 9 inch.
 
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Old May 17, 2008 | 10:05 AM
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I just upgraded to 31 spline axles from 28 splines over the winter.
 
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Old May 17, 2008 | 10:26 AM
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Originally Posted by duste
I've had nothing but 2wd's and several rear gear changes over the years and have found both 28 and 31 spline axles. Not sure but the 31 may be part of the 150 HD with the 6050 GVW. I know my truck has the factory power train with a 3.50 LS 31 spline 9 inch.
I have the 6150 GVW package and I still got stiffed with 28 splines.
 
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Old May 17, 2008 | 11:50 AM
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It depends on what options came on the truck. If you're looking for 31's then start with the 4wds - as I don't remember ever seeing a 4wd w/ 28 spline. That doesn't mean the genious that is ford never did it though. Trying to find 31 spline in a 2wd is more of a crapshoot. You may get lucky and find one with 31's - you may not.
 
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Old May 17, 2008 | 06:07 PM
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All 300 6 cylinder trucks that I have checked are 28 spline. V8 trucks are 31 spline.
 
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