rearend conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

my68c10 · 06-26-2004, 10:47 AM

new to the board so i hope this works.
i am wanting to put a rearend from a 81-87 pick-up under my 68 c10. my ? is has anyone used one of the conversion kits, and how did it turn out. i haven't seen this kit on any truck, and until i see one or talk to someone who has used this kit, i'm not buying one. the rearend is actually from a 91 surburban and i am trying to keep the drive train in line.-efi 350-700r4-342posi all under my 68. thanks for any help .

walker · 06-26-2004, 12:17 PM

GM 12 bolt is a fine rear, and is available in many gear ratios. Parts are easy to get, they fit the truck easily, disk brakes are available for them, lockers are easy to get. So, why is it you want to change?

SCOTI · 06-26-2004, 01:31 PM

Do you really need to swap? What is the current ratio of your 68 12-bolt? If it's 3.73's, that's a bunch of work for a very similar ratio. If you consider the $$ for replacement saddles for the rear end, the time it takes to grind off the old leaf spring saddles, welding the new ones on, swapping the rears, bleeding the brakes, re-hooking up all the remaining suspension, it doesn't seem worth it.

I would be willing to bet a lot of guys w/late model trucks & 3.42's would prefer the 3.73's anyway. Food for thought.

my68c10 · 06-26-2004, 01:36 PM

the main reason for changing is want to run ss crager wheels. i know i could just change the axles but i have the rearend and if the kit works i'd try it. only other positive is that the rear brakes will have the bigger pads. so have you seen the kit on any trucks. thanks for the reply

*1972C10* · 06-26-2004, 03:29 PM

I put a late model 95 rearend in my 68 SWB it wasnt a big deal at all I took and torched the pads off the 12 bolt and reused them .. then made a panhard bar bracket out of angle iron and welded it to the axle tube Used a 3/4 ton type panhard bar

When i swaped mine it was for a rachet locker 3.73

ChevLoRay · 06-26-2004, 04:49 PM

Get a rearend from a 71-72, and you'll have the bolt pattern you want AND they will swap, bolt for bolt, assuming you have a coil spring rear suspension.

So, you already have 5-lugs on the front?

my68c10 · 06-26-2004, 05:10 PM

yes, the frontend came from the 91 surburban and it fit very well. i think i had to egg shape one set of holes in the frame

krue · 06-26-2004, 05:20 PM

Welcome to the board from South Mississippi! I am with ChevloRay just get a 71-72 rearend unbolt yours and bolt it in it's place. But where there's a will (and a welder) there's a way.

Tx Firefighter · 06-26-2004, 05:44 PM

He has the rear end already!

It would be cheaper for him to swap over to the later rear end. The conversion parts are much cheaper than buying a 71-72 rear end. Besides, you can pretty much guarantee that the 91 Suburban rear end he already has will have less wear and tear on it than a 71-72 rear end. It's 20 years newer.

Early Classics will have everything you'll need, including the special rear end saddles like the earlier trucks use. Just call their tech line and they'll fix you up with what you need.

*1972C10* · 06-27-2004, 03:28 AM

If you need more details on how to do it without buying anything Let me know.

I have some before and after type pics of my swap and it came out premo.

06-26-2004, 10:47 AM	#1
my68c10 Registered User Join Date: Jun 2004 Location: monticello, arkansas Posts: 8	rearend conversion new to the board so i hope this works. i am wanting to put a rearend from a 81-87 pick-up under my 68 c10. my ? is has anyone used one of the conversion kits, and how did it turn out. i haven't seen this kit on any truck, and until i see one or talk to someone who has used this kit, i'm not buying one. the rearend is actually from a 91 surburban and i am trying to keep the drive train in line.-efi 350-700r4-342posi all under my 68. thanks for any help .

06-26-2004, 12:17 PM	#2
walker Registered User Join Date: Jul 2003 Location: north of Phx AZ about 30 miles Posts: 698	GM 12 bolt is a fine rear, and is available in many gear ratios. Parts are easy to get, they fit the truck easily, disk brakes are available for them, lockers are easy to get. So, why is it you want to change? __________________ Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold

06-26-2004, 01:31 PM	#3
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,094	Do you really need to swap? What is the current ratio of your 68 12-bolt? If it's 3.73's, that's a bunch of work for a very similar ratio. If you consider the $$ for replacement saddles for the rear end, the time it takes to grind off the old leaf spring saddles, welding the new ones on, swapping the rears, bleeding the brakes, re-hooking up all the remaining suspension, it doesn't seem worth it. I would be willing to bet a lot of guys w/late model trucks & 3.42's would prefer the 3.73's anyway. Food for thought. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

06-26-2004, 01:36 PM	#4
my68c10 Registered User Join Date: Jun 2004 Location: monticello, arkansas Posts: 8	rearend the main reason for changing is want to run ss crager wheels. i know i could just change the axles but i have the rearend and if the kit works i'd try it. only other positive is that the rear brakes will have the bigger pads. so have you seen the kit on any trucks. thanks for the reply

06-26-2004, 04:49 PM	#6
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Get a rearend from a 71-72, and you'll have the bolt pattern you want AND they will swap, bolt for bolt, assuming you have a coil spring rear suspension. So, you already have 5-lugs on the front? __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

06-26-2004, 03:29 PM	#5
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	I put a late model 95 rearend in my 68 SWB it wasnt a big deal at all I took and torched the pads off the 12 bolt and reused them .. then made a panhard bar bracket out of angle iron and welded it to the axle tube Used a 3/4 ton type panhard bar When i swaped mine it was for a rachet locker 3.73

06-26-2004, 05:10 PM	#7
my68c10 Registered User Join Date: Jun 2004 Location: monticello, arkansas Posts: 8	yes, the frontend came from the 91 surburban and it fit very well. i think i had to egg shape one set of holes in the frame

06-26-2004, 05:20 PM	#8
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Welcome to the board from South Mississippi! I am with ChevloRay just get a 71-72 rearend unbolt yours and bolt it in it's place. But where there's a will (and a welder) there's a way. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

06-26-2004, 05:44 PM	#9
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	He has the rear end already! It would be cheaper for him to swap over to the later rear end. The conversion parts are much cheaper than buying a 71-72 rear end. Besides, you can pretty much guarantee that the 91 Suburban rear end he already has will have less wear and tear on it than a 71-72 rear end. It's 20 years newer. Early Classics will have everything you'll need, including the special rear end saddles like the earlier trucks use. Just call their tech line and they'll fix you up with what you need. __________________ I'm on the Instagram- @Gearhead_Kevin

06-27-2004, 03:28 AM	#10
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	If you need more details on how to do it without buying anything Let me know. I have some before and after type pics of my swap and it came out premo.



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