2010 Sierra (tires Rubbing) Aftermarket

[Ski-Doo-Rider]

I have a 2010 sierra 1500 slt I bought more aggresive tires. (pro comp xtreme a/t) stock size 265 65r 18 I bought 305 65r 18 tires. I got pro comp 6001 offset rims and 4inch lift on the truck. Everyone said that this size tire should not rub. But it rubs on the inside wheel wells. Has anyone ever had this problem? what can i do to fix this? I checked too see if i could get a smaller size but pro comp does not offer smaller than (305) for that size rim.

Thanks for all the help