Author Topic: 10 bolt vs 12 bolt vs 14 bolt?  (Read 16008 times)

Offline moneyg77

  • Newbie
  • Posts: 45
  • Newbie
10 bolt vs 12 bolt vs 14 bolt?
« on: January 14, 2015, 01:59:59 AM »
So im in need of a rear end rebuild. I have an 81 k10 longbed stepside 350,4spd, 208 w/ 6'' lift and 35's . For the longest time ive been debating just rebuilding my current 10 bolt w/ 3.73's vs finding a 12 bolt (which i found 2, $170 per). then i found a 14 bolt from a chevy van 2500 for $150 on cl. Any suggestions? All help is appreciated.
1981 K-10 longbed stepside 350/465/208/quadrajet. 6"lift, 35" BFG, custom exhaust
1983 K-10 swb 4"lift
1986 lwb fleetside

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #1 on: January 14, 2015, 05:41:18 AM »
i would go with the 14 bolt BUT its going to be a 8 lug axle. then you need to match the ratio so you need to buy a 8 lug front axle. then you need new tires/rims
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline moneyg77

  • Newbie
  • Posts: 45
  • Newbie
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #2 on: January 14, 2015, 06:54:43 AM »
Why would I need new tires?
1981 K-10 longbed stepside 350/465/208/quadrajet. 6"lift, 35" BFG, custom exhaust
1983 K-10 swb 4"lift
1986 lwb fleetside

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #3 on: January 14, 2015, 07:55:22 AM »
16" rims for the ¾ vs 15" for the ½ ton. you can get 15" 8 lug but now your talking about more money
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Jason S

  • Senior Member
  • ****
  • Posts: 1561
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #4 on: January 14, 2015, 09:14:45 AM »
i found a 14 bolt from a chevy van 2500 for $150 on cl.

You might want to check overall width and spring spacing for the van 14-bolt before purchase. I seem to recall there were some differences between the truck and van axles... 

Since you're looking and researching, many of the 88-up Chevy/GMC light duty 2500 (and some 1500 trucks) had a 6-lug, semi-float 14-bolt rear axle. It would be stronger than the 10 or 12-bolt, but it'd require moving the spring hangers and shock mounts. 
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #5 on: January 14, 2015, 02:51:29 PM »
88+ are a different width i think
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline moneyg77

  • Newbie
  • Posts: 45
  • Newbie
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #6 on: January 14, 2015, 08:47:09 PM »
Ok, so it might be a no go. His 14 bolt is off of an '01 chevy van..i might just go with the 12 bolt posi's i found.
1981 K-10 longbed stepside 350/465/208/quadrajet. 6"lift, 35" BFG, custom exhaust
1983 K-10 swb 4"lift
1986 lwb fleetside

Offline Jason S

  • Senior Member
  • ****
  • Posts: 1561
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #7 on: January 14, 2015, 09:47:41 PM »
88+ are a different width i think
There is a slight difference in the 88-up truck versus the 73-87. 

Ok, so it might be a no go. His 14 bolt is off of an '01 chevy van..i might just go with the 12 bolt posi's i found.
My $0.02,
If you're going to keep the 6" lift and 35's, then a 14-bolt would be the better long term solution. 

Here's a recent thread in case you missed it:  http://forum.73-87chevytrucks.com/smforum/index.php?topic=30117.0;topicseen
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
10 bolt vs 12 bolt vs 14 bolt?
« Reply #8 on: January 15, 2015, 09:33:18 AM »
http://offroaddesign.com/catalog/14boltspringperches.htm

Buy these

Cut off the old ones
Bolt the 14 ff under your truck with the driveshaft installed and get he pinion angle wjere it should be and tighten down U bolts

Have a mobile welder come over and weld it

We are doing that now.  But I actually found non running a k10 wih a FF14 in with the perches and shock mounts relocated and the hub modifed so the wheel has  the same  width as the front axle
 so we bought it as a parts truck 

   
You will have to get  different rims and maybe different tires
You can buy aftermarket steel 15" rims that are 8 lug
But sometimes 15" won't fit on a FF axle and you also gotta swap the front hubs and rotors to 8 bolt

Someone on pirate is selling a kit to convert the FF14 to 6 lug AND disc brakes for about $350

That's a deal. You're gonna spend more than that switching to 8 lug rims
Plus 16 inch tires cost $100 each more than 15"s


Sent from my iPhone using Tapatalk
« Last Edit: January 15, 2015, 02:24:56 PM by roundhouse »

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #9 on: January 15, 2015, 09:36:32 AM »
If I was going to do something custom and put a little bit of welding work into it to make it fit, I would do the AAM 14-bolt axle out of the 2001 and newer trucks.  There are 2 versions: the 2nd generation 11.5 AAM and the 3rd generation 10.5 AAM.  These axles are similar to the Corporate 14-bolt, but they do not have the support bearing for the pinion like the Corporate 14-bolt.  These axles have the advantage of having factory disc brakes and also the ability to run an e-locker!
« Last Edit: January 15, 2015, 09:38:04 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #10 on: January 15, 2015, 07:20:17 PM »
by time you do all this you could buy a matching set of 8 lug axles for $250-$500 but then you have to get new rims and maybe tires. you can pick up a matching 6 lug for prob a little less then the 8 lug axles and keep your rims and tires and be done
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline roundhouse

  • Senior Member
  • ****
  • Posts: 1474
  • Newbie
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #11 on: January 16, 2015, 09:20:43 AM »
Yep
We swapped in 8 lug axles
Before I realised that 16 " tires are $100 more than 15s

What a ripoff.   There is actually LESS material in the tire but it costs more

Every inch increase in rim diameter above 15 adds $100 to a tire

We blew two 12 bolts driving totally normal on paved roads with 33s

So no real choice but to go 14 bolt
Silly me.   Thought a 12 bolt was as good as a 9" ford


Sent from my iPhone using Tapatalk

Offline moneyg77

  • Newbie
  • Posts: 45
  • Newbie
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #12 on: January 18, 2015, 01:32:16 AM »
Im kind of excited guys, for once in all the chaos. I found dana 44/14ff axles off of a 77 3/4 ton. I also found 8 lug 15" wheels in the same town my parents live. Did I find something promising? I started a separate post asking what I should offer for the axles. They have 3.73 gears and came off of the same truck. Thanks
1981 K-10 longbed stepside 350/465/208/quadrajet. 6"lift, 35" BFG, custom exhaust
1983 K-10 swb 4"lift
1986 lwb fleetside

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #13 on: January 18, 2015, 02:17:57 AM »
how much are they asking?
i think a good price is $250-$300
cant remember since its been so long but i picked my set up with 4.10 for 200 or 300 at a junkyard. knew the people and one boy who worked there was my childhood best friend and he was at one point (when his dad passed) co-owner of the place.
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline moneyg77

  • Newbie
  • Posts: 45
  • Newbie
Re: 10 bolt vs 12 bolt vs 14 bolt?
« Reply #14 on: January 18, 2015, 02:48:06 AM »
They're asking 500 for the axles and 150 for the wheels, two different sellers
1981 K-10 longbed stepside 350/465/208/quadrajet. 6"lift, 35" BFG, custom exhaust
1983 K-10 swb 4"lift
1986 lwb fleetside