First off I'm the new guy here, looking to see if I can find help here.

I am the engineer for my fire station and one of our squads is a 1990 Suburban 2500 4x4.

I do have a few questions and I hope this is the right place,

First off we have a rear heater its all beat up, was wondering is its easy to replace / find a new one?

Tires are going to be on the list to get, is there a bigger size that would work?

Was thinking of a little lift, what would be decent without having to change awhole hell of a lot.

In advanced thanks for the help!