I just bought a set of new wheels for my 05 G35x... Avant Garde M310. Front is 18x8.5 and rear is 18x9.5. I have at least a 1.5" drop all around but might be raising it a few notches because I keep breaking cv boots from the odd axle angles from the drop. I did a search and came up with 245/40 for the front, and 275/40 for the rear from a member on the forum. I am not very good with the math so I am double checking... what tires sizes would be recommended for me?

Thanks!

Update: Called Discount Tire in my area and they crunched some numbers and came up with 225/45/18 for the front and 255/40/18 for the back. Let me know if anyone has something to contrast the information they gave me.