10 bolt to 12 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bringit · 04-06-2005, 10:54 AM

What does it take to change from a 10 bolt to a 12 bolt? Is it just bolt in and play or is there some modifications that need to be made. And is 300$ a good price for a 12 bolt a local salvge yard?

Esteban86K5 · 04-06-2005, 12:08 PM

Why are you planning on changing it?

A 12 bolt and 10 bolt are pretty interchangeable. You will probably have to get a different u-joints because the 12 bolts caps are larger then than the 10 bolts caps. But other than that it will swap right in. $300 seems WAY too steep for J/Y axle. Around here you can get them for 100-150.

Hoods69BadBowTie · 04-06-2005, 12:14 PM

Yeah, it should be an easy swap. 300 $$ seems pretty steep to pay for one too. I have seen them go for like 150-200 $$$ tops up here.
-Later

Esteban86K5 · 04-06-2005, 01:30 PM

it's actually the 10 bolts u-joints caps that are larger then the 12 bolts caps. So you would need a different u-joint.

*gn4u2c* · 04-06-2005, 02:08 PM

you can buy the u joint at napa it's 14.99 spicer 372 I think

I have several 12 bolts with diffrent ratios right now I sell them for $100.00 in good condition.

bringit · 04-06-2005, 02:12 PM

What about a 1 ton 14 bolt axel my dad has one for free he just told me about . Has anyone done this swap, whats involved and do I use the 1 ton springs? Thanks for the advice.

Esteban86K5 · 04-06-2005, 02:22 PM

A little more involved for the 14 bolt but still could be a bolt on deal. You need to find out 2wd or 4wd and the year. I;'m pretty sure that it;s the 1 tons that have the different spring perch width than your truck. So you would need to cut off the old spring perches and weld them at the correct width. The u-joint will aslo need to be replace, I belive it's part bumber 447 from NAPA. If it's 2wd then your shock mounts won't match up either so you will have to redo those also.

Esteban86K5 · 04-06-2005, 02:24 PM

No you don't need the 1 ton springs to do this swap. Another thing i forgot to mention is the e-brake. I have a 14 bolt from a 73 in my 86 blazer and i had to modify the e-brake to make it work. Some 14 bolts have the correct cables that will work on your truck. You justneed to look at the axle and see if it will work. Take some measurements on the perches and check the shocks and make a decision from there.

bringit · 04-06-2005, 03:31 PM

Okay thanks, my dad said he also had a truck that needed the perches moved so I was wandering. I know a good welder so getting it changed shouldnt be hard.

Esteban86K5 · 04-06-2005, 04:17 PM

The spring perches and shock mounts would have to be moved on the 1 ton. Only difference between 2wd and 4wd perches are the amount they hang down from the axle tube.

04-06-2005, 10:54 AM	#1
bringit Registered User Join Date: Apr 2004 Location: Edmond, Oklahoma Posts: 105	10 bolt to 12 What does it take to change from a 10 bolt to a 12 bolt? Is it just bolt in and play or is there some modifications that need to be made. And is 300$ a good price for a 12 bolt a local salvge yard? __________________ 85 chevy K10 350 crate, headman headers, street avenger carb, accel distrib , rebuilt 700r4, on 33" Super Swamper TSL's, 4 inch Pro Comp lift, shocks, and steel braided brake lines. Last edited by bringit; 04-06-2005 at 10:55 AM.

04-06-2005, 12:08 PM	#2
Esteban86K5 Registered User Join Date: Oct 2003 Location: Bakersfield Posts: 133	Why are you planning on changing it? A 12 bolt and 10 bolt are pretty interchangeable. You will probably have to get a different u-joints because the 12 bolts caps are larger then than the 10 bolts caps. But other than that it will swap right in. $300 seems WAY too steep for J/Y axle. Around here you can get them for 100-150. __________________ Be American Buy American My Pics

04-06-2005, 12:14 PM	#3
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Yeah, it should be an easy swap. 300 $$ seems pretty steep to pay for one too. I have seen them go for like 150-200 $$$ tops up here. -Later __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

04-06-2005, 01:30 PM	#4
Esteban86K5 Registered User Join Date: Oct 2003 Location: Bakersfield Posts: 133	it's actually the 10 bolts u-joints caps that are larger then the 12 bolts caps. So you would need a different u-joint. __________________ Be American Buy American My Pics

04-06-2005, 02:12 PM	#6
bringit Registered User Join Date: Apr 2004 Location: Edmond, Oklahoma Posts: 105	What about a 1 ton 14 bolt axel my dad has one for free he just told me about . Has anyone done this swap, whats involved and do I use the 1 ton springs? Thanks for the advice. __________________ 85 chevy K10 350 crate, headman headers, street avenger carb, accel distrib , rebuilt 700r4, on 33" Super Swamper TSL's, 4 inch Pro Comp lift, shocks, and steel braided brake lines.

04-06-2005, 02:08 PM	#5
gn4u2c Account Suspended Join Date: Mar 2003 Location: southern pa Posts: 698	you can buy the u joint at napa it's 14.99 spicer 372 I think I have several 12 bolts with diffrent ratios right now I sell them for $100.00 in good condition.

04-06-2005, 02:22 PM	#7
Esteban86K5 Registered User Join Date: Oct 2003 Location: Bakersfield Posts: 133	A little more involved for the 14 bolt but still could be a bolt on deal. You need to find out 2wd or 4wd and the year. I;'m pretty sure that it;s the 1 tons that have the different spring perch width than your truck. So you would need to cut off the old spring perches and weld them at the correct width. The u-joint will aslo need to be replace, I belive it's part bumber 447 from NAPA. If it's 2wd then your shock mounts won't match up either so you will have to redo those also. __________________ Be American Buy American My Pics

04-06-2005, 02:24 PM	#8
Esteban86K5 Registered User Join Date: Oct 2003 Location: Bakersfield Posts: 133	No you don't need the 1 ton springs to do this swap. Another thing i forgot to mention is the e-brake. I have a 14 bolt from a 73 in my 86 blazer and i had to modify the e-brake to make it work. Some 14 bolts have the correct cables that will work on your truck. You justneed to look at the axle and see if it will work. Take some measurements on the perches and check the shocks and make a decision from there. __________________ Be American Buy American My Pics

04-06-2005, 03:31 PM	#9
bringit Registered User Join Date: Apr 2004 Location: Edmond, Oklahoma Posts: 105	Okay thanks, my dad said he also had a truck that needed the perches moved so I was wandering. I know a good welder so getting it changed shouldnt be hard. __________________ 85 chevy K10 350 crate, headman headers, street avenger carb, accel distrib , rebuilt 700r4, on 33" Super Swamper TSL's, 4 inch Pro Comp lift, shocks, and steel braided brake lines.

04-06-2005, 04:17 PM	#10
Esteban86K5 Registered User Join Date: Oct 2003 Location: Bakersfield Posts: 133	The spring perches and shock mounts would have to be moved on the 1 ton. Only difference between 2wd and 4wd perches are the amount they hang down from the axle tube. __________________ Be American Buy American My Pics



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