I got 275/35 Toyo T1R on my 05 g35, and left the stock brigstone 225/40 in the front because they weren't worn out a whole lot. whenever i change lanes my car pulls back to the lane i originally was...not sure if this has to do with alignment or different thread on toyo and brigstones..

 

you should be fine running two different brand tires in the front/rear as long as the left/right tires match up.

 

yeah my rear left and right are toyo t1r and front are stock tire that it originally came with 225/40...maybe its my alignment