I am changing the rear diff. fluid, seafoaming, changing the oil, and installing a new throttle body. I took the rear diff cover off last night and this is what I found:

The oil smells so burnt and is very dark. And im confused about the gears, It says 3.55 in the glove box, but nothing about LSD. Am I just dumb? What is the thing next to the ring gear? It doesnt look like an open diff?

 

Jack up the back end and turn one wheel, if the other spins in the opposite direction it's open. If they turn the same way you have LSD, btw you'll have to shift the tranny into neutral to do this.

 

im nearly positive thats an open diff

 

from what i see it doesnt look too bad. inspect it further and look for any chips or excessive scraping. Had a 04 hemi come in the shop last week that had almost no teeth left.

 

So I did everything but the throttle body. I took mine off but couldnt get the adaptor separated from it to put onto the new one so I had to order a new one. Here is the rear diff painted:
I think it looks pretty sweet. How long should do I really have to wait for the RTV so set up? It says 24 hours until it fully dries, but can I put the fluid in before that and move the truck or would it be best to wait till tomorrow afternoon?

 

I would wait. You dont want to risk screwing all your work on the paint. just give it the required time.

 

Yeah Im going to wait till tomorrow afternoon to do it.

 

I see your bumper has been living up to its name

 

Oh and this is what a LSD Diff looks like

 

Haha yeah it does a good job. I bought it with the one on the left, but the one on the right was me.