‘77 C10 12 bolt to 14 bolt conversion

[Rich77]

Hi guys,

it seems like it might make sense to change out my rear end.
How much different is a 14 bolt full floating axle with 3.73 gears and posi (which is gt4 g80 axle code) compared to my C10 12 bolt?
The 14 bolt is out of a 1989 GMC suburban c20 3/4 ton 2 wheel drive.
Is it a drop in fit? Are the leaf spring saddles and shock mounts in the same location?

Is there a drawing comparing them?
I searched with no luck.

thanks!

 

[Customblue]

The FF will be a direct swap but the driveshaft will need to be shortened if I am correct. At least it works like that on the k series

 

[Frankenchevy]

The u joint may also be a different size. You can get a hybrid u joint to accommodate both size yokes or have the drive shaft yoke changed if the driveshaft needs to be shortened.

 

[Rich77]

Thanks, guys.

I think this is an ok article on it-
https://lugnut4x4.com/axles/axle-swap-tips-and-advice/

 

[Craig 85]

What are you looking to do? You will need 8 lug wheels new U-bolts and spring plates, etc. I know in the 88 and up trucks (new body style), did offer a 14 bolt semi float with 5 and 6 lug options. I believe the spring perches are different. The 454SS pick ups had them in a 5 lug set up.

 

[Rusty Nail]

Y u no haz pix?