Big Question
 

So I have a HUGE question. I am wanting to lift my 2007 New Body Style GMC Sierra 2500HD... BUT its a northern truck so it is super rusty underneath it but the outside looks fine. Should I still spend $4000 on wheels , tires, and the lift? or am I just wasting my money? Thanks for your time.

Welcome,

You could always think about cleaning it up underneath and coating it?

thanks
 

how would I go about cleaning it up? wire brush it or ??

A drill mounted wire brush wheel will clean you off pretty well and close to bare metal. I would then coat with motor oil or some sort of a rust preventative spray. Rust-oleum makes one but I'm not sure how well it works.

I would just try and find a spray applicated truck bed liner or HD coating and go to town. You'll never get your movable components but your frame rails etc are what you're most likely worried about