Axle swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chevyman63 · 10-25-2007, 01:16 PM

Can anyone tell me what modifications, if any, are needed to install axles from a '79 truck onto a '72 Jimmy.

Burt4x4 · 10-25-2007, 02:41 PM

The front will bolt right in, your brake line fittings should work but may need to change the bajo bolt.
The rear your going to need to cut off the spring perches and move them inward adout 1 1/2" and probly the shock mounts will need changing...depends.
Other than that..can't think of anything else other than brake harware??

Chevyman63 · 10-25-2007, 02:48 PM

Thanks for the help Burt. Now to pass on the info and see if it is worth it or not.

Thanks to you as well Mark. I knew I could count on everyone here.

**Yukon Jack** · 10-25-2007, 02:47 PM

Is the 79 a 1/2 ton or 3/4 ton? If 3/4 ton, you will need a conversion u-joint for the rear driveshaft to axle location.

When I did a 3/4 ton swap to my 70 K5 I found my stock hard lines wouldn't bolt up to the rubber lines. I went ahead and just made up new hard lines with the right fittings.

Burt's dead on about the rear axle spring perches, unless your 79 happens to be a 1 ton, then the spring perches are in the right position.

It's a pretty straight forward swap.

10-25-2007, 01:16 PM	#1
Chevyman63 Can't wait to retire!! Join Date: Feb 2003 Location: Corunna, MI Posts: 1,575	Axle swap Can anyone tell me what modifications, if any, are needed to install axles from a '79 truck onto a '72 Jimmy. __________________ 2009 4x4 Chevy Crew Cab 6.0 1989 4x4 Siverado (270,000 miles) 1972 4x4 Blazer 2007 Chevy Cutaway 1 ton 1970 Corvette (sons project) RIP - CLR 10/11/09

10-25-2007, 02:41 PM	#2
Burt4x4 Registered User Join Date: Feb 2000 Location: Modesto, CA Posts: 1,842	Re: Axle swap The front will bolt right in, your brake line fittings should work but may need to change the bajo bolt. The rear your going to need to cut off the spring perches and move them inward adout 1 1/2" and probly the shock mounts will need changing...depends. Other than that..can't think of anything else other than brake harware?? __________________ 1972 K5 MPFI454/Sm465/Np205/D60/14FFd/Re-Centerd H1s w/Swamper Iroks

10-25-2007, 02:48 PM	#3
Chevyman63 Can't wait to retire!! Join Date: Feb 2003 Location: Corunna, MI Posts: 1,575	Re: Axle swap Thanks for the help Burt. Now to pass on the info and see if it is worth it or not. Thanks to you as well Mark. I knew I could count on everyone here. __________________ 2009 4x4 Chevy Crew Cab 6.0 1989 4x4 Siverado (270,000 miles) 1972 4x4 Blazer 2007 Chevy Cutaway 1 ton 1970 Corvette (sons project) RIP - CLR 10/11/09 Last edited by Chevyman63; 10-25-2007 at 03:15 PM.

10-25-2007, 02:47 PM	#4
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	Re: Axle swap Is the 79 a 1/2 ton or 3/4 ton? If 3/4 ton, you will need a conversion u-joint for the rear driveshaft to axle location. When I did a 3/4 ton swap to my 70 K5 I found my stock hard lines wouldn't bolt up to the rubber lines. I went ahead and just made up new hard lines with the right fittings. Burt's dead on about the rear axle spring perches, unless your 79 happens to be a 1 ton, then the spring perches are in the right position. It's a pretty straight forward swap. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14



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