installed a new Kohler, round seat toilet. The old toilet was an elongated seat. The tank is about 3" from the wall and is wobbly.
That's kind of interesting. Are you SURE you have it installed correctly? The toilet needs to sit on the flange. Home Depot has an installation guide here.
Rocking is generally caused by a flange set too high. As shown in the picture above, the flange should sit ON the finished floor.
The shape of the bowl (round or elongated) doesn't change the relationship between the toilet and the wall.
The tank is wobbly. The seat is firm. Why would there be so much room behind the tank and wall? There was approx 2" before but now the tank is about 3" from the wall. Am I worried about nothing?
Oh, just the tank. Then you might just need to tighten the bolts a bit. Don't get crazy, you can crack the tank or base. If something seems wrong, take it apart and try again.
Thank you. I'll try that.