I'm running 1 and 3/4 on mine, they are hub centric and I don't think it is to much stress.. I wouldn't go over 2. also your not going to gain any travel with wheel spacers. I run mine because my set up was made for a 0 offset wheel, and I need the spacers to keep the wheels out of the tie rods.. IMHO running spacers gives you no performance gain, and the are for looks and so the are ghey..