Hey,
Check out my web and profile pic.
I've got 24" Dropstar DS02 mounted to Toyo 305/35/24 rubber. . . . . . rubbed just a very little bit for the first couple days. . . . on the front wheels ONLY. You can fit up to a 30" on the rear. . . . . I know cause I've already tried. . . . just looked goofy with 30" rear and 24" front.
If you look inside your front wheel wells, you will see a couple "plastic" retention "bumps" on the side closest to the door. Depending on your final tire/wheel size, one of these may/may not rub off. . . . . it does not compromise the integrity of your wheel well.
Additionally, I went to my dealer and got an ADDITIONAL set of pressure sensors so that I could leave the set in my factory 20's and have a set in the Dropstars. I will run the factory rims/tires in the winter months and the Dropstars the rest of the year. The additional sensors cost me $124 but it's worth it.
Regarding the TPMS. . . . take it to your dealer, they shouldn't charge you more than $40 bucks to reprogram. They have to change the tire size in your CPU. This will keep your speedo calibrated also.
The ONLY WAY we were able to get the pressure sensors sync'd was to follow the manual process in the owner's manual. The GM Tech tried doing in the automated way with his handheld computer several times and it didn't work.
Hope this helps!!
Josh
Chesterfield, MO (St. Louis)