Hi Thanks for the info, I had found that very helpful website.
I decided to keep my stock 20x9.5 inch factory wheels and try 305-55-20, which is very close to the 275-60-20 stock tires height but about 1.2 inches wider.
My truck has the Max trailer package and is also lowered 2 inches.
The tire shop is willing to install the front tires and let me test drive for rubbing and if they rub too much, they will take them off.
Going to the tire shop Friday.