70 vs 77 Rear Axle Width???
Lead Driver
Joined: Sep 2003
Posts: 5,241
Likes: 3
From: Other side of the sunrise
I believe that the 70 2wd has narrower frame rales then the 77 2wd. If this is true, then you could grind off and remount/weld the spring perches and shock mounts. Take a tape measure and measure from left spring perch to right to verify. Spring and shock mounts should be the only difference.
By the way, why are you doing this? If it is a broken axle or differential that needs to be replaced, then you could do that without changing the housing. Would be alot easier. Of course make sure that the axles have the same axle splines before doing that. They could also be different.
By the way, why are you doing this? If it is a broken axle or differential that needs to be replaced, then you could do that without changing the housing. Would be alot easier. Of course make sure that the axles have the same axle splines before doing that. They could also be different.
Postmaster
Joined: Apr 2002
Posts: 3,613
Likes: 6
From: Coal country
Oldfords is correct - but the information is incomplete.
Not only is the frame narrower on the '72 and earlier trucks, but the entire axle housing is as well.
Look closely at the earlier trucks, 59 to '72, from the rear. The rear axle is narrower than the front. Some think they look a little goofy going down the road.
This swap has been covered a lot in the '61 - '66 forum, but from the other way around, trying to put a '73 to '79 axle into a '72 or earlier truck. That forum, and the '67 - '72, is where I spend most of my time. Come on over and visit.
I believe you will find issues with wheel setback on the rear axle if you choose to use the '70 axle in your '77. It will be narrower, and the backing plates will be closer to the springs - perhaps requiring special wheels.
Good luck on your search.
Not only is the frame narrower on the '72 and earlier trucks, but the entire axle housing is as well.
Look closely at the earlier trucks, 59 to '72, from the rear. The rear axle is narrower than the front. Some think they look a little goofy going down the road.
This swap has been covered a lot in the '61 - '66 forum, but from the other way around, trying to put a '73 to '79 axle into a '72 or earlier truck. That forum, and the '67 - '72, is where I spend most of my time. Come on over and visit.
I believe you will find issues with wheel setback on the rear axle if you choose to use the '70 axle in your '77. It will be narrower, and the backing plates will be closer to the springs - perhaps requiring special wheels.
Good luck on your search.
Thread Starter
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Senior User
Joined: Sep 2003
Posts: 364
Likes: 0
From: Hartland, MI
Thanks, I just need to switch to 4:10 gears and my buddy has a good 70 complete diff. I would just switch the entire thing if it would work. I have recently had my entire rear suspension out and new bushings in, so the bolts would be easy. Since the widths are diff, I will just put new gears in my housing. Thanks Zac
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