10 bolt vs 12 bolt rear end?

[85 Money Pit]

I have a 1980 2wd Swb with 5.7 vortec / 4l60e. I have 10 bolt and 12 bolt end and both of them need to be rebuild. I just wondering which rear end is better and why.

[MikeB]

Originally Posted by 85 Money Pit

I have a 1980 2wd Swb with 5.7 vortec / 4l60e. I have 10 bolt and 12 bolt end and both of them need to be rebuild. I just wondering which rear end is better and why.

For a 350 with auto trans, an 8.5" 10-bolt is more than adequate. And it's lighter and more fuel efficient than a 12-bolt. Now if it's a 7.5" 10-bolt from a car or S10, then runaway, runaway!

Are both configured to bolt in to your truck -- right overall width, spring perches, lug configuration, etc? If so, I'd go with the one that has the correct gear ratio for your application.

[Matt Man]

The 12 bolt has larger axles and ring gear, while the 10 bolt has a larger diameter pinion gear I think. But, the 12 bolt usually doesn't break at the pinion gear. I would pick to rebuild the 12 bolt, but to rebuild the 10 bolt will be cheaper I think. Also in 1980 they were using 12 bolt axles still, so it would be more original to your truck if you are trying to keep it more stock. My 81 still has the 12 bolt.

[85 Money Pit]

Thanks guys, for your responses. I guess that I will stick with the 10 bolt rearend since it came with the truck. Plus, I have scored a brand new Eaton locker and Richmond 373 gear from my coworker for only 200 buck.

[rayfinseats]

Plus, I have scored a brand new Eaton locker and Richmond 373 gear from my coworker for only 200 buck. Well there ya go and by the way you suck. LOL. A 12 bolt is only slightly stronger than a 8.5 10-bolt but a govlock or an 8.2 10 bolt not too strong at all, 7.5 even worse.

[85 Money Pit]

LoL

[MikeB]

Originally Posted by 85 Money Pit

Plus, I have scored a brand new Eaton locker and Richmond 373 gear from my coworker for only 200 buck.

Locker or limited slip? Lockers can be scary on the street, especially cornering in the wet.

Do a lot of reading or find a guy who has done GM 10- and 12-bolts before. I've done three of them over the years, and while the job is not super-difficult, it does take the right tools, patience, and an understanding of exactly what you're doing and why. The entire pinion depth/crush sleeve thing was a mystery to me until I jumped into it. Same with pinion pre-load vs. final pinion nut torque. Not doing it right will result in noise or worse.

[PowerdbyChevy79]

if this is a daily I would not recommend a locker..i put a locker in my 82.. long story short I almost wrecked cause the truck tried to spin around when I had to brake suddenly one day..i pulled it back out.