About to pull the trigger on my tires online cant decide!!!! HELP
 

As some of you might remember I got a Rock krawler 5.5" kit for my mega, Im geting diamo 17 karate rims in the 18x10. Im going with the dick cepek fun country IIs. I was going to get 325/65R18s but the 37s look so good on these trucks.

The problem is I have a hemi, if I had the diesel id get the 37s for sure but im worried how well the hemi will push the 37s down the highway. On top of that if I went 37s should I get 4.88 gears instead of 4.56, do they even have 4.88s for out AAM axles?

Im going to be installing my lif saturday I think so I need to get my tires and rims ordered asap.