I've had 225 50 16 tires on 98 240sx with no problems and my suspension is worn enough the car looks lowered. These tires where mounted on the stock se wheels when I bought the car. I didn't like the way the tires buldged out, so I replaced them with stock size tires (205) I had an extra set of 300zx na wheels with 225 50 16 tires on them and they fit fine as well. Only reason I'm not using them now is because the tires are bald.
I put a set of the Fuzions on my 300zx TT because I needed tires fast and didn't have a whole lot of mulah at the time. Very good tire for the money. They dont seem to grip as well as the dunlop sp 8000 I had before, but the treadwear rating is higher, and the sp8000 were crap when it was cold. The Fuzions might not be a great track tire, but more than adequate for daily driving.
Tomorrow I'm putting 17x9 +30mm offset wheels with 245 45 17 tires on the 240sx

It should be sweet.
I'll have to get some masking tape and put it on the front strut to show no rubbing.