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73-87 Chevy _ GMC Trucks => Projects Posts (NOT VEHICLES) => Topic started by: HAULIN IT on July 23, 2008, 12:03:09 am

Title: Rear End Swap (UPDATE)
Post by: HAULIN IT on July 23, 2008, 12:03:09 am
I had mentioned a while back that I was preparing for a 9" swap. Here are some photos as it went along. I built a jig to narrow 9" housings many years ago. On this one I used a 9" housing center, the GM truck axle tubes (so the U-bolts, plates ect. would be the stock size) turned upsidedown & Ford axle bearing ends. The center section is a 31 spline 3.70 gear for now (I may try a 3.89 later). The brakes are Crown Vic discs.
 (http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension001.jpg)
A couple shots of the homemade shock brackets:
 (http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension004.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension006.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension007.jpg)
I'm using Rancho RS9000 9 position shocks (mounted vertically)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension009.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension011.jpg)
While the lower U-bolt brackets were off, I made some "Cal-trac copy" traction bar mounts with a tie-down incorporated.
 (http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension012.jpg)
 (http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension013.jpg)
The rearend was installed on top of the springs & the rear hanger/shackle were turned over
 (http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension018.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension019.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension022.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension015.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension002.jpg)
Please excuse the "ratty" looking undercarrage, this is a stress relief, play toy, definitely not a show vehicle. The outcome is, I got it done just in time to test it at Norwalk Raceway this past weekend. It works GREAT! I'll post some more photos from the race when I get a chance. Lorne   
Title: Re: Rear End Swap
Post by: Stewart G Griffin on July 23, 2008, 10:49:22 am
i hearby dub this truck the "International Truck," due to it's mass conglomeration of parts from various manufacturers, although Oldsmoboggie is/was GM so it's ok.

i'm a little disappointed, not nessesarily in you, but they way the truck is turning out, especially in the rearward sections.

My personal opinion , not nessesarily factual experience,  is that with the 12" (or whatever size you are using) slicks, they (the slicks) will break free (spin) before the 12bolt would get damaged if in fact the engine is at the point where it is producing enough power to spin them.  But what do i know?  i've never gone faster than 13 secs and have only used 10 bolts.


What's next?  i hear toyota disks fit the chevy 10/12 bolt.  Not that it makes a difference now.
Title: Re: Rear End Swap
Post by: SUX2BU99 on July 23, 2008, 11:20:22 am
Well I'm pretty impressed. Some cool fabrication work going on there. Here I am trying to get thru just a simple-as-it-gets stock for stock rear end swap and you're mating GM axle tubes to narrowed 9" centre section, new shock mounts, cal-trac mounts n' stuff. Very cool!
Title: Re: Rear End Swap
Post by: VileZambonie on July 23, 2008, 03:50:38 pm
i'm a little disappointed, not nessesarily in you, but they way the truck is turning out, especially in the rearward sections.

 ??? What exactly do you mean?

Looks great man. Good job!
Title: Re: Rear End Swap
Post by: Captkaos on July 23, 2008, 04:15:38 pm
Looks Great!  Nice work!
Title: Re: Rear End Swap
Post by: 78 Chevyrado on July 23, 2008, 09:24:38 pm
Great lookin work!
Title: Re: Rear End Swap
Post by: choptop on July 23, 2008, 09:43:47 pm
very impressive. Id have never thought about mounting the gm tubes to the 9 in center...hmmmmm
Title: Re: Rear End Swap
Post by: 80stepsideguy on July 26, 2008, 12:53:47 am
Nice job your doing man, 2 thumbs up on your  work.

thanks
pat
Title: Re: Rear End Swap
Post by: HAULIN IT on July 26, 2008, 02:21:53 pm
Thanks for the complements guys! Some days that's what a guy needs to forge ahead. Chop, I started doing the "original tubes" on Mavericks & such, the 8" uses the same (if using 28 spline) axles, bearings, ect. as the 9". The problem with them is a posi for an 8" is nearly like hen's teeth & the gear selection isn't as good as the 9". What I would do is really just change the housing center, then came Camaro's & even a couple Vega's (the older ones have all 4 mounting arms on the tubes). Stewart, What have I done to my truck that disappoints you? Changing it from the stock? The Ford rear end? Each of us enjoy working on & personalizing our trucks or we would not do it or be on this site sharing ideas, ect.  I realize the Ford rear may not be for the die-hard GM guy, but it has some advantages.... Changing gears in an hour, if you break a carrier strap the housing isn't ruined, close gear spacing (3.70,3.89.4.11) the bolt-in axles, ect. I thought other parts (the shock mounting, rear hanger flip, ect.) may be of interest to some. I could see if I had chopped the frame off, put the biggest tires I could buy & leave the stock 305 that would not serve much purpose. After all, hotrodding in it's base form started by guys adapting more powerful, stronger, different parts to a vehicle they have to accomplish whatever it is they are after (looks,performance, ect.) I have mentioned before, I've got allot of auto hobby interests & am a well rounded hotrod guy... the truck being it started out life as a GMC is just part of it. Try to tell the streetrod guys that they can only use a Mustang II front if it's going under a Ford. My truck is a good, sound working piece that is used daily all summer, it suits our needs & desires. Most importantly...gives the wife & I quality time doing something we both like. Lorne   
Title: Re: Rear End Swap
Post by: eventhorizon66 on July 26, 2008, 03:06:01 pm
Looks like a top notch job to me.  Thanks for the pics.
Title: Re: Rear End Swap
Post by: comp on July 27, 2008, 11:16:11 pm
Looks like a top notch job to me.  Thanks for the pics.

 i agree,,can't wait to see more
Title: Re: Rear End Swap
Post by: GMCtruckinNDN on August 18, 2008, 01:14:47 am
Looks great, nice job!

Glad to see new modified is good thing to have.

I think that'll runs stronger, smooth ride and hope to win the race!
Title: Re: Rear End Swap (UPDATE)
Post by: HAULIN IT on September 01, 2008, 02:12:14 pm
Over the weekend I found time to make & install my traction bars. They are designed after ones that John Calvert gets credit for the original plan. Out of respect to John & Chris who sells Cal-trac bars, I have no intentions to do a step-by-step or discuss diamentions, ect. Besides, I didn't find a set, measure & copy them, so who knows...maybe mine don't work as good either. More or less a little encouagement for the do-it yourselfer. On a side note... I got these little rubber boots for the rod ends, Seals-it I think was the company, they are pretty slick. I stuck a needle tip grease gun along the edge & filled them up. Should work well to keep the grease in & the dirt & water out. Now back to the track next weekend to try them out. Lorne
 (http://i163.photobucket.com/albums/t285/HAULINIT/tractionbars035.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/tractionbars034.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/tractionbars033.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/tractionbars038.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/tractionbars041.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/tractionbars039.jpg)
Title: Re: Rear End Swap (UPDATE)
Post by: comp on September 01, 2008, 02:31:25 pm
looks Good
Title: Re: Rear End Swap (UPDATE)
Post by: Captkaos on September 02, 2008, 12:08:35 pm
Nice job!
Title: Re: Rear End Swap (UPDATE)
Post by: VileZambonie on September 02, 2008, 02:53:53 pm
Cool!
Title: Re: Rear End Swap (UPDATE)
Post by: DnStClr on September 02, 2008, 05:19:31 pm
Geez Lorne. More! More!!  :D
Title: Re: Rear End Swap (UPDATE)
Post by: JJSZABO on September 03, 2008, 09:50:52 am
IMPRESSIVE

WOW

What can I say?   GREAT JOB Lorne ;)
Title: Re: Rear End Swap (UPDATE)
Post by: SUX2BU99 on September 03, 2008, 11:28:56 am
Awesome awesome! Really dig those "cal trac" bars. So those work by preventing spring wrap, right? Yet they still allow regular movement of the spring and axle?
Title: Re: Rear End Swap (UPDATE)
Post by: Captkaos on September 03, 2008, 03:27:46 pm
Yes, that is what they do, the axle won't try to wrap since they are limited by the bar.
Title: Re: Rear End Swap (UPDATE)
Post by: DnStClr on September 03, 2008, 11:15:12 pm
I forgot to ask, how do you change out the gear oil in the diff case? Is there a plug on the front side?
Title: Re: Rear End Swap (UPDATE)
Post by: HAULIN IT on September 03, 2008, 11:53:10 pm
Don, Yes the cast iron (front) case has a fill plug about a 1/3 of the way up. You just fill until it starts to come out. As for the drain, originally you loosen the nuts & gently pry out on the bottom & let it go in a pan, just like you would a rearend cover. On most of the housings I build, I put a drain plug in the bottom so it's much neater to drain & virtuly all of it comes out, not leaving it level with the bolt flange like the original set-up. In the photo the center part of the housing is upside down. Lorne
(http://i163.photobucket.com/albums/t285/HAULINIT/truckrearsuspension001.jpg)
Title: Re: Rear End Swap (UPDATE)
Post by: MohterTrucker on September 26, 2009, 04:00:53 pm
Really nice work. Impressive fab skills. Nice shop, too.
How did flipping the rear hangers/shackles affect the height?
Also, do you have any pics of the rear brake setup?
Title: Re: Rear End Swap (UPDATE)
Post by: HAULIN IT on September 29, 2009, 06:49:45 pm
Thank You! I searched through my Photobucket, I don't have any pic's of the brakes, Sorry. They are basically unmodified '96 Crown Vic stuff.
 As for flipping the rear hangers...it would have to make the truck sit a little higher than a regular flip. If you look where the rear eye is compared to the frame & then look at a stock hanger/shackle, mine is lower (thus raising the truck) however the rear end being half way up the spring, it wouldn't be all that much at the wheelwell (1 1/2" or so I'm guessing). A lowering block of some sort could be used if needed. Here's a couple pictures to get an idea how it sits, however I have done an angled (front to rear) 2" body drop so you have to concider this when comparing ride height to other trucks. Lorne 
(http://i163.photobucket.com/albums/t285/HAULINIT/oldsweekend.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/oldsweekend012.jpg)