https://www.gnttype.org/numbers/rpo.html
Scroll to the bottom & you’ll know almost everything the car came with.
As for odd/rare, I’ll let the guru’s chime in on that one.
Sounds like a personal preference.
Can go up to 255’s in the rear. Some will push a 275 in the rear(need a wider rim for 275’s IMO). I run 275’s in the rear on an 8.5” rim. I run 235’s up front with no rub. That doesn’t work for all.
I’m still running on 15’s.
220ish. Your temp light come on?
Front mount? Thermostat working? Both fans working & working up to snuff? Radiator in good condition(no build up).
Some guys run RMI 25 to help with cooling.