Gear ratio change

So here's the deal. I have a 2001 DC auto. It has 4.10s. I would like to switch to 4.56s. I hunted them down at a local salvage yard. My question is, I have a rear locker, the donor pickup does not. Will mine work with the 4.56s? Also, is there a difference in the front differential between 2.7s and 3.4s? Thanks in advance!

 

Nope, the non locker axle has a different differential.

 

I believe the front differential is the same, but yeah, no dice on the rear.

 

If you want to swap it's easier (and probably cheaper in the long run) to have someone like East Coast Gear Supply do it all. I believe they can send you a 3rd member and you just send yours back for a core.
Gears are also pretty tricky to install correctly, especially if you don't have a full set of shims and the proper tools.

 

I'm in need of a good 3rd member. Will you have an extra for sale? i don't really care what gears are in it because my truck is 2wd.

 

Ok but can I take the guts out of the differential and put them in my existing one? I have plenty of tools and a place to do it. I'm a farmer from Nebraska with plenty of experience mechanically just haven't ever torn into differentials except for putting axle seals in

 

Don't know many folks who have tools of this nature lying around. http://www.jegs.com/i/JEGS/555/8165...W6-Zj8Kp32lQJoEwL7BjPLbyllRuhQhtJBBoC3g_w_wcB

Or know how to use them.

 

My brother went to college for mechanics and worked at it for 10 years. We have a kit similar to that

 

OP,
Your 3rd is an 8.0 and the non-locker 3rd is an 8.4. R&P's will not interchange from one to the other.

Good luck.

 

Just like Ritchie said, the R&P are different sizes. The only way you can use a non elocked rear diff in an elocked rear end is to swap the entire axle housing. Same goes for just using the R&P out of the one you bought