bagdb2200
+1y
Those have a BS of 5.88", so a front space of 3.12"
The Caddy wheels like in your sig have a front space of 3.03".
So those 18's will stick out .09" farther than the Caddy wheels. I don't know about on your truck but on mine with Caddy wheels my tires hit the bedsides when layed out, so you'd have to flare them a little bit to fit those 18's.