tire size?
 

I just bought some new bbs wheels, 18x8.5F and 18x9.5R, my question is what tire size would look good and perform well? I was thinking maybe 275 or 285 in the rear and perharps 245 in the the front, opinions?

245/35 and 275/35 would be pretty good choices, maybe even 255/35 and 285/30, depending on your offsets.

there a 38 offset, i would like to get 285 on there if posible, you think the 255 would fill out the front wheel wells nicely?

With those widths and offset, I would stick with 225/40 or 245/35 up front, 265/35 in back. 275/35 could be really close to rubbing, depending on exact tire brand and camber.

Would rolling the rear fenders allow me to run a 285? or is 275 the max?

A few manfs allow it, but I would not run a 285/30 on a 18x9.5 wheel.