Why would my Chevy Colorado 07 tires have excessive cupping on inner edges?

[BamaChevy]

I maintain this Colorado well. 33,200 miles. Tires rotated/balanced religously/tire pressure monitored. Last time I took it for service at dealership they said front tires were badly worn. Swapped rear tires to front end. Now rear tire (now on front left) is also badly cupping on inside. I took it to Chevy dealer for investigation. They blew it off as a tire maintenance issue. I suspect there might be alignment/suspension issues. What do I do to make sure it is right before I put 4 new tires on it?

[John L]

Have a 4 wheel tire alignment the Colorado's have been having some issues. Also have you tire shop verify the specs they have for the alignment. Our local shop tried to go with the proper specs and instead had to change them some to correct the problem on one of our customers colorado.

[boogie_4wheel]

Check the front end alignment to see if it is within spec.

[Chev M]

get the truck 4 wheel aligned even thou you cant align rear end to se if its off i have seen manny tire issues if alinment is on id check front suspension ive done manny aloignment and only a couple came back with tire issues