Need Help/Suggestions 1971 C20

[C.20]

Hows everyone doing today I got a problem this morning My HO52 blew apart and i knew this was going to happen and i bought a rear end i bought a Dana 60 out of a 86 c20 and the person told me that would work and yesterday of course right before it blows he says it wont fit and i asked a fabricator and he said that all i need was a new yoke and U joints please if someone can help me on what i should do that would be great

-C.20

[factorystock]

Put in another good HO52 (4.10 ratio most V8 autos 69-72). This is a simple swap requiring absolutely no fabrication, can be done with basic tools in a hour or 2. Anything else will require fabrication, could get very expensive if you have to pay someone to do it.

[Mike C]

You need to figure out exactly what you have. An '86 would not have had a Dana 60 in it but a GM corporate 14 bolt. It could have been a semi-float or it could be a full-float depending on what GVWR the truck was.

The '86 axle will have 2 1/2" wide spring perches rather than 2 1/4" spring perches. The shock mounts will be in a different place as well.

If a semi-float most likely a 1330 u-joint and if a full-float most likely a 1350. You can get a conversion u-joint that should let you keep your existing driveshaft. Maybe. It depends on length of snout on axle and how much clearance and spline engagement that you have.

[special-K]

If you bought that rear since you joined here, you should have asked these questions before buying rather that go by the word of the seller. It's rare for an HO52 to blow. If you can find another that would be best. An '86 wouldn't have a Dana60, it would have a 14-bolt. Make sure exactly what you have. Any GM rear after '72 will at minimum need the shock mounts changed from staggered, one forward/one rearward, to both forward and the spring mounts will need to be changed. No new yoke should be required unless the rear has issues. Fr any give rear there will be only one correct yoke. Any changing would be done by changing driveshaft end to work with the yoke. none of this is necessary if you buy a conversion u-joint. Those are available with one side to match your rear and the other to match your driveshaft

[C.20]

Originally Posted by factorystock

Put in another good HO52 (4.10 ratio most V8 autos 69-72). This is a simple swap requiring absolutely no fabrication, can be done with basic tools in a hour or 2. Anything else will require fabrication, could get very expensive if you have to pay someone to do it.

I can not find another one i tried so many places and in NC i cant find another one

[C.20]

Originally Posted by special-K

If you bought that rear since you joined here, you should have asked these questions before buying rather that go by the word of the seller. It's rare for an HO52 to blow. If you can find another that would be best. An '86 wouldn't have a Dana60, it would have a 14-bolt. Make sure exactly what you have. Any GM rear after '72 will at minimum need the shock mounts changed from staggered, one forward/one rearward, to both forward and the spring mounts will need to be changed. No new yoke should be required unless the rear has issues. Fr any give rear there will be only one correct yoke. Any changing would be done by changing driveshaft end to work with the yoke. none of this is necessary if you buy a conversion u-joint. Those are available with one side to match your rear and the other to match your driveshaft

I heard that also but the thing is i blew up the spider gears and i don't think you can buy spider gears for the rear online or any were so im stuck but I am going to look at the new rear and see what i can do

[C.20]

Originally Posted by factorystock

Put in another good HO52 (4.10 ratio most V8 autos 69-72). This is a simple swap requiring absolutely no fabrication, can be done with basic tools in a hour or 2. Anything else will require fabrication, could get very expensive if you have to pay someone to do it.

The thing i have been wondering is would a HO 72 Diff fit in a HO 52 because if that was the case it would be so much easier

[C.20]

And honestly guys me and my dad don't even no what rear end is in the truck he thinks it's a ho52 but I don't think it is maybes he's right I have no clue

[factorystock]

Ok, its pretty simple to tell what you have. If the rear differential looks like a round ball, it is the Ho52. Very similar to a Ford 9". IF rear differential looks like the V pattern, it is a Spicer 60.

[mrolds88]

99% sure the H072 and H052 diffs are the same. The 52 is the single rear wheel version and the 72 is the dual wheel one. There are SOME things that will interchange between them and the 14 bolt. I know that if it is equipped with a No spin, the spiders will swap, but you have to use the 14 bolt axles. They are different spline. 17 vs 35 (I think).