Gear choice decisions
with out writing a maifesto, ejnoy:
https://spicerparts.com/calculators/transmission-ratio-rpm-calculator
to more completely answer your question, based on the information above: the difference betwixt the 4.56's and 4.10's at an assumed 3000rpm (your cruise speed at 50 with the 4.56's) would be about 8mph, or 400rpm, give or take. note this does not take into account actual variances in tire height that is reported as spec vs in reality. so your mph and/or rpm may vary
slightly.
i can't answer to the bigger tires specifically, but i know that there's limited space with factory rims and 255 seems to be about it width wise, but i'm fairly certain i've seen 28" tall tires out back without hacking anything up too much.