wheel spacer questions


Yeah, I got my used pair of hubcentrics for $53 but they're worth $180 when new!
 
Hey guys i have a mustang gt 2000 with cobra rims, 18x9. I want to get them right flush with the fender. I own a body shop and i want to hammer out the wheelwells as well as i had done with my transam. (the metal part which sticks out into the wheelwell) i have seen some with 1.5 inch spacer but im not sure of the rim size. I even found 2 inch spacers but i do not know if that is too big. I am thinking of going with 1.5, what do you guys think?