1972 C20 Rear Axle Swap
 

Hello everyone. I just completely dissasembled my 1972 C20. It has a DANA rear end with leaf springs. I have been looking at a lot of forums and still have not found an answer to my problem/dilema. I currently have a 350 engine with a 350 trans. I plan to drop in a 700R4 and WANT to upgrade my rear end to an 8-lug disc brake set up. But I don't want to buy the 8-lug conversion kit. I was looking at buying a 2002 (or similar year)Chevy HD semi-floating rear end (runs about $500). Anyone ever done such a swap?
I don't plan to haul anything.
I don't want a 5 or 6 lug.
Thanks.

Re: 1972 C20 Rear Axle Swap
 

(free bump for you)
Sorry I haven't done this swap.
Anyone else?

Re: 1972 C20 Rear Axle Swap
 

I can't offer any 'experience' for this exact conversion but have been invloved w/similar rear-end type swaps.

It seems your doing things right by maintaining consistency. Using a newer 8-lug disc rear rear is a simplified way to replace the current 8-lug housing & achieve your budget friendly 8-lug disc goal. The over-all width of the 2 different housings could be an issue (or may not be). You should still be able to haul anything the original 8-lug C20 housing was capable of hauling w/exception of a loaded trailer because of the 700r4 (not known to survive long when used in heavy, towing applications).

Re: 1972 C20 Rear Axle Swap
 

Have to bump this up, I am thinking about doing the same swap, many of the newer diffs are locking too which would be nice
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Re: 1972 C20 Rear Axle Swap
 

I'm pursuing the same swap. I measured the wheel mount to wheel mount on one at work today. They are approx 68 3/8". Hope that helps.
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Re: 1972 C20 Rear Axle Swap
 

I'm a little late to the discussion, but another option is to use the early 14 bolt full floater (8 lug) and the bolt-on adapter plates discussed here (scroll down a ways) and available at www.rightgear.com (note: their website does not show this product). These plates adapt the 2002 and later 2500 HD disk brakes to the early 14 bolt single rear wheel axles and maintain the 67" wheel mounting surface to wheel mounting surface width of these axles, which I believe is what was in the earlier C20s (I have an '82/5 C20 and it is a direct bolt in). Compared to other disk conversions for these axles, the 2500 HD disks feature two pistons and a cable-actuated "drum in a hat" emergency/parking brake.

I've got all the parts and am in the process of performing this conversion. I bought a complete used 14 bolt full floater single rear wheel axle for $200, a lightly used (80k miles) 14 bolt from a 2004 2500 HD for $300, and the adapter plates from right gear for $265 (including shipping). Since I also switched the 4.10 ring and pinion to 3.73s, installed new bearings and seals, and put in a lightly used posi, it is not as "budget" as I would have liked, but it should be stout and trouble-free for a long time. While I could have gotten just the 2500 HD brakes, the conversion uses a lot of the brake-related parts (including the hoses, lines, and shields), so getting the whole axle seemed cost-effective in the long run - besides, I should be able to sell the left over axle housing with gears, axles and hubs. I'll post some pics later.

As someone else noted, the width of the later axles is a tad over 68", meaning the wheels will mount about 1/2 to 3/4 of an inch wider on each side compared to stock if you go this route, which shouldn't be a problem for our trucks. Of course, you'll need to cut the spring perches and shock mounts off the later axle and weld new ones on in the correct locations.

In regard to towing/hauling with a 700R4, I bought my C20 in '97 and it had a lot of miles then. I towed/hauled regularly (not professionally) as a weekend DIY warrior and the original "weak series one" 700R4 finally died about 5 years ago. I replaced it with a later 700R4 specifically designed and built for towing/hauling (the "Heavy Hauler" from Performabuilt Transmission) - it has been troublefree ever since.

Re: 1972 C20 Rear Axle Swap
 

I recently picked up a 2001 E250 semi float Dana 60 from the local u pull it. ($127.00!!)
It is approx 67" wide, disc brakes with internal ebrake. Being that it is from a van it has 8x6.5 bolt pattern. I'm shortening mine 8" but stock it should be better than the newer Gm.
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Re: 1972 C20 Rear Axle Swap
 

Wait did he just say F$%^ was better than GM! Who let this guy on here!?!? ha ha j/k

Re: 1972 C20 Rear Axle Swap
 

Yeah I know but it's still a Dana!!
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Re: 1972 C20 Rear Axle Swap
 

And the e250 and e350 are always in the junkyards old wore out work vans.

Re: 1972 C20 Rear Axle Swap
 

Any new ideas?

Re: 1972 C20 Rear Axle Swap
 

Curious myself. I have a 1970 C20 with Dana 60 (4.11) that I want to switch to 3.55 or so. Disc brakes would be a bonus.

Re: 1972 C20 Rear Axle Swap
 

Bump-it has only been a year. Any updates?

Re: 1972 C20 Rear Axle Swap
 

Does anyone know if the leaf springs will bolt up from a 2002 chevy 2500 or will the springmounts need moved?

Thanks for any info..

Re: 1972 C20 Rear Axle Swap
 

Does anyone know if the leaf springs will bolt up from a 2002 chevy 2500 or will the springmounts need moved?

Thanks for any info..

Re: 1972 C20 Rear Axle Swap
 

I would start a new thread with that question. It is not really related to this thread and you may get more answers. I would say they won't fit your mounts.
Jimmy