Question about tire sizes for tire guru's
 

I am running 245/35 in the front rite now with 275/35 in the rears... if I put on 255/40 in the front with 275/35 in the back will it look different? performance difference? just need some help since i am getting a great deal on these tires slightly used and want to know if its okay for me to slap them on my car.

come on guys.... i know someone has a little input..