Is a 4wd rearend the same as 2wd? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

HuggerCST · 09-24-2010, 11:38 AM

Are there any differences that may cause problems in a swap? Both are '72 model, both 8 lug 3/4 ton rearends, (Eaton, I believe) but one is out of a 4 wheel drive, and one is out of a 2 wheel drive. Both are leaf spring rearends.

**68350** · 09-24-2010, 01:22 PM

It shouldn't make any difference if they are both leaf spring rear ends.

HuggerCST · 09-24-2010, 03:49 PM

Quote:

Originally Posted by 68350

It shouldn't make any difference if they are both leaf spring rear ends.

That's my thought too, I just wasn't sure about the length, shock mounts, driveshaft, etc.

**68350** · 09-24-2010, 05:27 PM

Shock mounts may be different but the width should be the same. The driveshaft may be different if the two trucks have different transmissions.

**Stocker** · 09-24-2010, 06:15 PM

Both shock mounts are forward on my '72 K20 (Eaton).

*sharpie1972* · 09-24-2010, 06:43 PM

Spring perches will need to be moved. Sharpie

Livrat · 09-24-2010, 11:04 PM

Sharpie is correct.. 2WD leaf spring rear ends have wider spacing than 4x4's on the perches due to the "bulge" in the rear frame rails
Although if its out of a longhorn.. they are the same as 4X4.

HuggerCST · 09-24-2010, 11:41 PM

Good info, thanks guys, that helps a lot.

09-24-2010, 11:38 AM	#1
HuggerCST Registered User Join Date: Jul 2001 Location: North Louisiana Posts: 4,501	Is a 4wd rearend the same as 2wd? Are there any differences that may cause problems in a swap? Both are '72 model, both 8 lug 3/4 ton rearends, (Eaton, I believe) but one is out of a 4 wheel drive, and one is out of a 2 wheel drive. Both are leaf spring rearends. __________________ Wynne 70 CST short fleet Hugger orange & white, 350/350, ps, pb, air, tilt, tach/vac/speedwarning, original buckets, AM/FM, oak bed floor, shoulder belts, 3.5"/5.5" drop, 20" American Racing VN425s. Build thread 53 Chevy shortbed 69 Camaro Click here to subscribe Chevy GMC International Truck Club Louisiana Charter Member http://www.louisianaclassictruckclub.com Last edited by HuggerCST; 09-24-2010 at 11:46 AM.

09-24-2010, 01:22 PM	#2
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Is a 4wd rearend the same as 2wd? It shouldn't make any difference if they are both leaf spring rear ends. __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

09-24-2010, 05:27 PM	#4
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Is a 4wd rearend the same as 2wd? Shock mounts may be different but the width should be the same. The driveshaft may be different if the two trucks have different transmissions. __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

09-24-2010, 06:15 PM	#5
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,692	Re: Is a 4wd rearend the same as 2wd? Both shock mounts are forward on my '72 K20 (Eaton). __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

09-24-2010, 06:43 PM	#6
sharpie1972 Account Suspended Join Date: Apr 2007 Location: Powell, Wyoming Posts: 4,973	Re: Is a 4wd rearend the same as 2wd? Spring perches will need to be moved. Sharpie

09-24-2010, 11:04 PM	#7
Livrat Member #1049 Join Date: Jun 2000 Location: Troy Montana Posts: 3,940	Re: Is a 4wd rearend the same as 2wd? Sharpie is correct.. 2WD leaf spring rear ends have wider spacing than 4x4's on the perches due to the "bulge" in the rear frame rails Although if its out of a longhorn.. they are the same as 4X4.

09-24-2010, 11:41 PM	#8
HuggerCST Registered User Join Date: Jul 2001 Location: North Louisiana Posts: 4,501	Re: Is a 4wd rearend the same as 2wd? Good info, thanks guys, that helps a lot. __________________ Wynne 70 CST short fleet Hugger orange & white, 350/350, ps, pb, air, tilt, tach/vac/speedwarning, original buckets, AM/FM, oak bed floor, shoulder belts, 3.5"/5.5" drop, 20" American Racing VN425s. Build thread 53 Chevy shortbed 69 Camaro Click here to subscribe Chevy GMC International Truck Club Louisiana Charter Member http://www.louisianaclassictruckclub.com



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.