14 bolt questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Kalums · 10-01-2025, 06:48 AM

So I'm putting a 14 bolt full float 10.5 in my 1971 GMC K2500 and I've run into a quandary... My current drive shaft has 1350 u joints and the axle has a 1410 yoke ( I can tell because of the distance between the ears of the "new" yoke) I'm currently replacing the bearings/seals on the original pinion and was wondering if I should keep the 1410 u bolt style yoke and just run the Neapco conversion ujoint ($35) or swap in a new 1350 u bolt style yoke ($85-180). My current driveshaft angle seems to be 6.4 degrees... But I'm not 100% sure how to measure it. I simply had the truck on a (relatively) level concrete pad and stuck an angle finder on the drive shaft. Any and all help would be greatly appreciated.

**Palf70Step** · 10-01-2025, 07:27 AM

Since you are doing all the bearings and seals, I would change it over to the 1350.

HO455 · 10-01-2025, 09:44 AM

Here are some links to help with the drive shaft angle measurements.

https://spicerparts.com/calculators/...gle-calculator

https://youtu.be/SDjBHT5-u_4?si=INL3zLxzb8LSxQuH

https://youtu.be/SH2VIoWOQ0E?si=vwJCrMW1xT3z9n_T

Here is how I set up my Burban's driveline. Scroll to post 348 to start. Then in the 2nd link post 671 when I converted to a single drive line and finishing on post 682.

https://67-72chevytrucks.com/vboard/...lstein&page=14

https://67-72chevytrucks.com/vboard/...lstein&page=27

Hope this helps. Good luck and post your findings!

Kalums · 10-01-2025, 06:54 PM

Quote:

Originally Posted by Palf70Step

Since you are doing all the bearings and seals, I would change it over to the 1350.

That is the way I am leaning... It was just that the conversation u-joint was $35 vs the new yoke is $85+.

Kalums · 10-01-2025, 06:55 PM

Quote:

Originally Posted by HO455

Here are some links to help with the drive shaft angle measurements.

https://spicerparts.com/calculators/...gle-calculator

https://youtu.be/SDjBHT5-u_4?si=INL3zLxzb8LSxQuH

https://youtu.be/SH2VIoWOQ0E?si=vwJCrMW1xT3z9n_T

Here is how I set up my Burban's driveline. Scroll to post 348 to start. Then in the 2nd link post 671 when I converted to a single drive line and finishing on post 682.

https://67-72chevytrucks.com/vboard/...lstein&page=14

https://67-72chevytrucks.com/vboard/...lstein&page=27

Hope this helps. Good luck and post your findings!

You sir are freakin' awesome thank you so Much.... These will help alot

10-01-2025, 06:48 AM	#1
Kalums Registered User Join Date: Jun 2024 Location: Phoenix,AZ Posts: 343	14 bolt questions So I'm putting a 14 bolt full float 10.5 in my 1971 GMC K2500 and I've run into a quandary... My current drive shaft has 1350 u joints and the axle has a 1410 yoke ( I can tell because of the distance between the ears of the "new" yoke) I'm currently replacing the bearings/seals on the original pinion and was wondering if I should keep the 1410 u bolt style yoke and just run the Neapco conversion ujoint ($35) or swap in a new 1350 u bolt style yoke ($85-180). My current driveshaft angle seems to be 6.4 degrees... But I'm not 100% sure how to measure it. I simply had the truck on a (relatively) level concrete pad and stuck an angle finder on the drive shaft. Any and all help would be greatly appreciated.

10-01-2025, 07:27 AM	#2
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 48,486	Re: 14 bolt questions Since you are doing all the bearings and seals, I would change it over to the 1350. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

10-01-2025, 09:44 AM	#3
HO455 Registered User Join Date: Feb 2016 Location: Portland Oregon Posts: 12,411	Re: 14 bolt questions Here are some links to help with the drive shaft angle measurements. https://spicerparts.com/calculators/...gle-calculator https://youtu.be/SDjBHT5-u_4?si=INL3zLxzb8LSxQuH https://youtu.be/SH2VIoWOQ0E?si=vwJCrMW1xT3z9n_T Here is how I set up my Burban's driveline. Scroll to post 348 to start. Then in the 2nd link post 671 when I converted to a single drive line and finishing on post 682. https://67-72chevytrucks.com/vboard/...lstein&page=14 https://67-72chevytrucks.com/vboard/...lstein&page=27 Hope this helps. Good luck and post your findings! __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377



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