Nice looking truck!
Definitely stamped UCAs as someone else already mentioned. Standard opinion on lifts is 2.5” or less, unless you change UCA’s.
You should be able to fit 275/70R18 or 285/65R18 with a 1.85” level (think Bilstein 6112 or 5100).
If you want more height, the 4.5” CST is...