Will a 2002 lariat rear end work on a 2008 ram 1500. Also what are years that are interchangeable for my 2008 Dodge Ram 1500 5.7 L, I’m pretty certain 04 to 08 are good

 

Lariat is Ford. Ford rear ends would require some pretty extensive fab work to go under your truck.

What's wrong with the rear diff that is currently in your truck?

Moving this to third gen ram section for ya.

 

Gonna assume you mean Laramie. 2002 to 2008 rears are physically swappable, but at some point around 2006 or after they switched the rear speed sensor from one over the ring gear to the hubs, which won't work for you.