Important to know if it is 2007 Classic or 2007 new style.
Major difference.
I have a 2007 Classic with LBZ - Allison combo.
It has been a great truck and a huge powerhouse. I had a 2003 LB7 prior and it was not as good as this one.
I did however have to put an injector pump in it 2 months ago at 301,000K on the clock. And one injector.
Prior to that I have put only one glow plug in it in 300000K
I have had people try to buy mine off me several times. Simple 3 word answer. Not for sale.
I would buy the one you're looking at in a heartbeat, if it is an LBZ