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Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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| | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 | Will a '72 C20 3rd member work and what should I be aware of before I drive to Phoenix to buy it? I live in San Diego. Before I pull the axles on my truck can anybody tell me how many splines should these axles be? The guy in Phoenix is pulling an axle out of his 1972 C20 to tell me how many splines are on his.
Steve Glover
| | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 | Oh, the 1972 C20 yoke takes a Spicer 5-178X u-joint. Is that the rear u-joint for my '55?
Steve Glover
| | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 | Sorry! I didn't think that I could just call Napa and find out. I called, and yes, Spicer 5-178X is a cross for my '55
Steve Glover
| | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 | I can just pull one and find out. Thanks for your help. Sometimes I put the cart in front of the horse!
Steve Glover
| | | | | Joined: Apr 2005 Posts: 7,441 Bolter | | Bolter Joined: Apr 2005 Posts: 7,441 | Man, you gotta slow your roll and give the guys time to answer! 
Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
| | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 |
Steve Glover
| | | | | Joined: Jun 2005 Posts: 168 'Bolter | | 'Bolter Joined: Jun 2005 Posts: 168 | Make sure that chunk in Phoenix is a 4.10. Just because it's a '72 doesn't mean it's a 4.10. Most of these trucks came with 4.57 gears
Liquidated my projects
Now looking for a decent '47-'55.1 3100, 3600, or 3800
| | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 | I will do just that! I'll do my homework to try to make sure. I'll ask the guy to count the teeth on ring and pinion.
Steve Glover
| | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | Mine is a 4.10 from a 1972 3/4 Ton. The universal is the same. | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | Looking for whatever year and model donor is a good place to start, but just a start.
The 4.10 gears could be in many other vehicles (with same size Eaton axle) or the truck you think will have them won’t necessarily.
For sure check numbers on ring gear and or count teeth to know for sure what you found.
I’ve heard of more 4:10 pumpkins coming from various other trucks than I have the fabled 70-whatever 3/4 ton.
They’re still out there, but open your search so as to not miss the easy pickings. | | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 | Good advice, thank you both.
Steve Glover
| | | | | Joined: Jun 2000 Posts: 2,773 'Bolter | | 'Bolter Joined: Jun 2000 Posts: 2,773 | Didn't the 72 also come with the 12 bolt Dana axle? Be certain he has the 10 bolt. Also, the ratio is stamped on the ring gear. Your differential is identified as a HO52/72. Went from 47-72. When you make the swap I recommend a new pinion seal with a reddi-sleeve. IIRC you will need to use the trunnion from your truck.
Last edited by Fred T; 12/16/2018 4:37 AM.
Fred
52 3600
69 C-10
| | | | | Joined: Dec 2018 Posts: 15 New Guy | | New Guy Joined: Dec 2018 Posts: 15 |
Steve Glover
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