Rear end for LS

[faun_cee]

What is a good donor rear end for an LS swap? it is coil spring, so i believe its easier...

[special-K]

The one that's in it.

[Slowguy]

I'm in the middle of a swap. I'm just using my same rear end that has 3.73 gears in it. I decided to pull it all part and replace bearings, seals, gaskets, rear dif cover, and intall a new eaton trutrac carrier. Just about finished with it. From what I've read, it's not so much the rear end that needs swapped but possibly the gear ratio depending on what transmission you decide to use with your swap? Also, (and I'm not this far along yet) you need to decide how to get the power from the trans to the rear end. There are some decisions to make in deciding whether to get a custom driveshaft, center carrier issues, and maybe might be able to get by with some yoke modifications to original stuff. I'll know more on this later.

[MARKDTN]

Originally Posted by special-K

he one that's in it.

Agree. If you add overdrive you may want a different ratio-but might be just fine. What is wrong with what you have?

If you decide to change, 3.42 is a nice overall gear for a driver with relatively tall tires and overdrive.

[special-K]

You asked what "rear" not what "gear". A 12-bolt is fine. What ratio do you have now? What transmission? What tire size? What will your primary use be?

[faun_cee]

Thanks for the help! but just to be clear i can use the 69 stock rear end? I had an uncle tell me it needed to be changed but hes never done one so im glad i asked.

[faun_cee]

Originally Posted by special-K

You asked what "rear" not what "gear". A 12-bolt is fine. What ratio do you have now? What transmission? What tire size? What will your primary use be?

no Idea the gear ratio... im assuming stock bc ive had the truck for 20 years and it still has its I6 with a 350 turbo trans. the tires in the back are 295/60/R15
would i need to switch to disc brakes?
just trying to figure out how much work i actually need. ill probably buy an entire car for the motor. what else would i need or can use from the donor?

[OldMoparsRule]

I have a 2001 4x4 Silverado with the 5.3, 4l60, with 3.73 gears. That is what came standard on the Z71.

If you are putting the LS/4l60 combo, then most came with either 3.23, 3.55 or 3.73. I am sure there are some with higher of lower gear ratios....

As someone else mentioned, we really need to know what combo LS you are going with, to be able to suggest an appropriate ratio. As far as the current axle, you should be fine.

I doubt you will need disk brakes in the rear at this point. It would be a great upgrade in the future, but you will have enough on your hands with the LS swap.

I hope this helps.

Thanks,
OldMoparsRule!

[Problems]

Originally Posted by faun_cee

Thanks for the help! but just to be clear i can use the 69 stock rear end? I had an uncle tell me it needed to be changed but hes never done one so im glad i asked.

Yes the stock ‘69 rear end is a truck 12 bolt. In stock form it’s good for somewhere in the neighborhood of 500hp. With new axles and c-clip eliminators people run a bunch more threw them. After that your looking at a new housing like a Moser or Strange. So as long as your LS isn’t running some crazy power you already have a great rear end.

As far as gears like a bunch of guys have posted it really depends on your trans, tire height, and what you plan to do. A rock crawler and a highway cruiser need very different gears.

[special-K]

You'll probably e using the motor, transmission, harness, and computer from the donor. So you will have overdrive. My guess is you have 3.08s because of the TH350, but maybe with 6cyl 3.73 was standard. If 3.73s I think you'll like that. 3.08s might be good but kinda lanky with O/D. You will want to go to front disc brakes. The rear discs are an option for later on down the road you may or may not want. But not a concern at this point

[faun_cee]

Originally Posted by OldMoparsRule

I have a 2001 4x4 Silverado with the 5.3, 4l60, with 3.73 gears. That is what came standard on the Z71.

If you are putting the LS/4l60 combo, then most came with either 3.23, 3.55 or 3.73. I am sure there are some with higher of lower gear ratios....

As someone else mentioned, we really need to know what combo LS you are going with, to be able to suggest an appropriate ratio. As far as the current axle, you should be fine.

I doubt you will need disk brakes in the rear at this point. It would be a great upgrade in the future, but you will have enough on your hands with the LS swap.

I hope this helps.


Thanks,
OldMoparsRule!

It will be the LS/4I60 combo, so it seems like it will be okay. i just want to cruise and showoff the car not its performance

[special-K]

Just freshen up that rear and you can focus on the swap.

[72blu]

the factory 12 bolt is plenty. with a 4L60 transmission, you have the advantage of an overdrive. You could get away with a 4.11 rear gear if you wanted and still be ok on the highway.