Tiny bounce in my new tires/rims!

So i have finally got my new XD Monster 2 rims 9" plus my 305/65 BF goodrich tires balanced and rolling! I do think I may have some minor tire/wheel bounce (on the straights not the turns); could this be just the fact that I have larger tires than the stock 275's? Or, could I need a suspension adjustment and possibly even a sway bar?

Oh yeah, 2014 TRD crewmax

 

no lift added and no leveling added. According to "the book" 305's are the largest I could go without the need for any of that. I did however have to trim out some of the plastic in the 2 front wheel wells. The plastic that sits at the front bottom of the well and backs up to the bumper.

 

You added unsprung weight with bigger wheels and tires, and probably got stiffer BFG's, which will react differently to bumps. Might need to play with the air pressure.