tire size for a 18

I just bought a set of 18s and they have a 225/40/18 on them.It is about a half inch from laying out in the front.Could I run a 215/35/18 on it or is that to small.The tires on it know hit the top of the finder whale and I dont really want to cut it out.

That should be fine if a 225 is already on there. Are they an 18x7.5?

yes they are.I just didnt know if i could possibly bind a wheel.I mean i dont drive it a whole lot but I will drive it to shows.Thanks for the answer

I have 215/35/18's on my hardbody,and they are nicer looking than a 40.

im runnin 215/35s on my astro. theyre 18x7s. rides well not too small of a profile

ok thanks for all the help.I googled a tire calculater and it said that that should give me the 1/2 inch I need thanks.Also does that sound right should that be about a half inch shorter

So will that give me the half inch I need