Swap Older Corporate 14 for New Corporate 14
 

Hello Experts! I'm in the process of doing an LS Swap for my 70 K10. I acquired a rolled 2011 Sierra HD for a screaming deal for the LS and electronic transmission. I want to also use the rear end (Corporate 14 BoltAAM 10.5) in place of my existing '79 Corporate 14 bolt. While I have already done the disc swap on my existing corporate (which I'm glad I did), I want the more powerful stopping power (and newer overall components) from the '11 rear end.

I already know I'll have to re-weld one of the shock mounts to move it from a rearward facing shock on the '11 to forward facing on my '70. I suspect I'll have to also replace with new spring perches as well and possibly change out the hub to keep my existing wheels based on the bolt pattern sizing.

Has anyone used a newer Corporate or even AAM in a 67-72? Anything else I should be thinking about or be aware of?

Attachment 1826406

Attachment 1826407

Re: Swap Older Corporate 14 for New Corporate 14
 

i have not used these . but seen guys talk about them . https://cutbros.com/shop?olsPage=pro...brake-adapters

Re: Swap Older Corporate 14 for New Corporate 14
 

Are the gear ratio's the same? Good chance the newer axle has a locker.

Re: Swap Older Corporate 14 for New Corporate 14
 

I know 3.73 and 4.10 are both available for this make/model/year but I heard that the 4.10 are pretty rare. My guess is this a 3.73. I'll be checking the sticker tomorrow to find out.

Re: Swap Older Corporate 14 for New Corporate 14
 

It's still a 10.5 not an 11. I had a 1050 in a 2004 3/4 dodge. The next year the 1150 was in everything and the only real difference between the 3/4 and one ton SRW became the suspension. Better emergency brake with the factory disc. Didn't answer your question, but I like the idea of the factory disc and e-brake too. Mine had 4.10s :chevy:



j

Re: Swap Older Corporate 14 for New Corporate 14
 

Thanks for the replies so far. I checked the RPO codes and turns out I’m one of the lucky ones with a 4.10 and also a limited slip as part of the package. Anyone know if width is going to be an issue?

Re: Swap Older Corporate 14 for New Corporate 14
 

Just recently put a 14B-10.5" from a later model 2500HD. Disc brakes are OK. May be user error but the '73 Dana 60 that was replaced had as good or better brakes even though they were drum. IMO.

The parking brake connections took a little figuring but work pretty well. I still park it in gear out of habit. Mine has the Gov Lock and 4.11s. No problems with it....yet.

The width is interesting though. Turned out to be within 3/4" of the front which got rid of the wide front axle - narrow rear look which I always thought was weird. The spring perches were way off. I cut them off (they are really thick) and welded in new AM ones.

All in all, I like the disc 14B. I never really considered the Eldorado calipers as an option for my truck. I run too heavy too often and Id rather have kept the drums if I hadn't gotten a smoking deal on the axle.

Hey Jeff, did the 11 - 11.5 axles have the bolt in pinion carrier? I know at the time, the bigger ring gear axles were non bolt in pinion.

Re: Swap Older Corporate 14 for New Corporate 14
 

I have heard that is one of the only differences and the pinion bearing setup, besides the massive 11.5 gear. I've never opened either of the AAMs. The 1150 is a monster. Does your 10.5 have the disc with drum e-brake?

I am running the drum in my 14bolt. I like the drums, I leg press my e-brake, and I like that. I'm running a hydroboost and I only get a slight rear end lock up on super hard quick braking with the bed empty.

The only reason I chimed in was I like the idea of the AAM1050 disc pads and shoes for e-brake. Plus I had 4.10s, just wanted to fortify that point too.

I don't think there is any reason to put your hands on one to bust it open. They are new plentiful and robust. I even feel like my 30 year old 14bolt is new! Now that I said that I'm in for trouble, I can feel it! :lol:


j

Re: Swap Older Corporate 14 for New Corporate 14
 

Yeah, thats the one I have. Big discs but the inner part of the rotor has the "drum like" shoes that are the e brake.

Id like to be able to "leg press" mine but I have the brake lever under the dash still. Not quite as effective.

Hey Rowdy, if you get a chance, could you see what the bore diameter of the master cylinder is? I have a 1-1/4" (maybe 1-1/8?) and that may be why my brakes seem a little soft?

All in all though, good axle. I worry more about the rest of the truck falling apart around the 14B.:lol:

Re: Swap Older Corporate 14 for New Corporate 14
 

Thanks guys!

Chris, I think the bore diameter is 1.5", which surprises me because I thought smaller bore meant more braking power...maybe I'm doing my math backwards. See below for a pic of the brake master cylinder and booster I pulled this weekend. I'll get a better pic of the entire setup when I have it cleaned up.

Good to know on the width. What did you do for your shock mount? Did you also cut and reweld that?

Also, I have 8 lug 6x165.1/170 spacing on my existing corporate. Does anyone know if I have to change those out?

Re: Swap Older Corporate 14 for New Corporate 14
 

If you need a way to correctly mount that hydroboost to your truck's firewall, I do make these that will accomplish the installation easily and correctly.

http://www.67-72chevytrucks.com/vboa...d.php?t=347484

http://www.67-72chevytrucks.com/vboa...d.php?t=347480

Re: Swap Older Corporate 14 for New Corporate 14
 

Thank you! I'd love to have something easy to swap in of course. Any problems with your option if I flip the brake booster upside down?

Also, really hoping I can somehow still use the pedal assembly from the 2011. I took some time to remove the rust and clean it up.

Re: Swap Older Corporate 14 for New Corporate 14
 

You can easily flip the hydroboost 180* with my booster bracket and hydroboost mounting plate. I think you'll have to do quite a bit of work and modifying to install the 2011 pedal assembly.

Re: Swap Older Corporate 14 for New Corporate 14
 

I swapped a AAM 14BFF from a 2005 GMC 2500 under my 72 K5. Its a little wider than the original axle. Its going to have metric brake lines and wheel studs. I also used a hydro-boost from the same truck with one of CaptainFab brackets. I used the original pedal from the 72 and made a custom rod. I haven't run the truck yet so I may to tweak the brake pushrod position for the correct leverage and pedal feel....