Stabilizer Bar add on to my 1500 Sierra ext. cab. Can I???

[Wires]

I don't think you'll notice much difference on washboards.

 

It might actually handle better since it'll help control the difference in L-R wheel movement rates during those situations.

[Spurshot]

I have the largest factory bar in the front OEM with the Vmax trailer pkg. I added a Hellwig rear bar. It handles much better in all conditions, but is especially noticable when loaded up on trips with all my hunting junk. Like others have said, you have to ensure you're not messing up the handling with severe understeer or oversteer. Mine worked out. A smaller factory front bar may not be as compatible.