wheel size

HI all! This is my first thread. So I hope I put in the right section. I'm looking to put some new rubber on 2016 F150. The truck came with 275/65R18 (32.1 x 10.8 with a 7" sidewall). I was thinking about going with a 20" wheel (really like the Fuel Contras) and 296/60R20 tire (34 x 11.6...