AuroraGirl
I'm Awesome
fun fact, in some year at least 95 GM started allowing a tech 1 or tech 2 to change the wheel size on at least GMC vans, I would assume trucks too. if you find a friend with a tech 2 you can correct your size. I corrected my uncles 95 GMC vandura to the size he had coincidentally put on and it fixed his speedometer readingIf the door tags are missing the RPO codes on glove door identify what factory originally installed.
With a tire sizing application or chart. You can mix and match, profile ( aspect) with width to get the diameter and footprint you want.
The 245 looks to narrow for my K2500.
I have 275/ 70 / 16. Tire width looks correct. Speedometer is 1.5 slower than actual GPS ground speed. I can live with that. Good luck.