I have a 2006 LBZ with 40k miles on it and was wondering if I need to be running any type of additive due to the lower sulfer diesel we get at the pump? If I am not, will it hurt the truck any or just the performance?
If so, then what additice should I get that is cost effective?

You dont have too, but it never hurts. For the money I reccomend PowerService in the silver bottle. You can get it at any autoparts store or wal-mart. It may make a little difference but you probably wont notice much.

Bio diesel or 2 stroke oil. Best bang for the buck compared to the "other" additives.

I would, stanadyne is my choice.I use it every fillup.

I've used Stanadyne and Opti-Lube XPD and they are both very good. You shouldn't lose performance. In most cases you will gain, although not very much.

Most additives will add to the life of your fuel system components, but it's difficult to measure how much. Biodiesel really shines in this area.

I use them for added insurance.

Here's why I run Stanadyne Performance. Over several long freeway trips last year I averaged right at 1.4 mpg more when I ran Stanadyne versus not running Stanadyne. That was equivalant to a little more than 2 gallons per tank difference for me. With #2 now at $4.60+ in my area, that is a savings of $9 per tank. It costs me $2 worth of Stanadyne to treat a full tank.

I agree with the performance comments. When I bought my 06 lbz we were still getting low sulfur fuel. When it disappeared and we got the ultra low sulfur fuel we have today I saw at least a 1.5 mpg drop. After reading of the possibility of seals drying out and loss of lubrication for the fuel system components with the new ultra low sulfur fuel, I tried stanadyne. I got very close to getting back the mpg's I lost with the new fuel. That along with keeping the fuel system clean and lubed was enough for me to keep using it.