I have 08 xl regular cab f150 was wondering what is the biggest rim i can put on? Is 24 too big will it rub or anything. Also i heard the truck rides differenetly?

 

The rim size doesn't really matter as much as the tire you put on the rim. Sure, 24's will fit, as long as the tire diameter doesn't exceed around 32-33 inches (4x4). Just watch your offset.

Yes, huge wheels with extremely low profile tires will handle differently. The will usually be more responsive cornering, but you will feel more of the bumps in the road. Also, you have to be much more carefull around potholes, since there is much less rubber between the road and your rims. One good bump, and you just scrapped a rim.