My rims came today. The specs are 18x8.5 +48 18x9 +31. Since i recently got into a accident and the tires are gone, i decided to put them on.

What size tire will fit my 350 that's lowered on eibach 250 springs?

 

Anything... the offset on your new wheels seem to be very gentle.

235/35/18 for fronts, and 265/35/18 for rears.

The front tire size is pretty much fixed, but you can play with a few different sizes on your rear sizes.

255/40/18
265/35/18
265/40/18
275/35/18
These are all the options for your rears. You nightmare will be finding a matching pare that will fit your budget, and prepare a heat gun in case you need to fix a minor rub.

Good luck with your shopping,

 

Awesome! Thanks Joseph. I sent you a PM.

Can i run 235/40/18 so i have a larger length of sidewall?