What do you have on it now?
I just love the latest version of the Dunlops, went out in a MPSS square setup and to me it felt like the tyres wanted to come off the rims when you start to push in the corners, all kind of squirmy with the weight of the car.
The general ride was better though, normal suspension mode felt like comfort and there was less tyre noise (not really a problem with your exhaust setup
)
Won't going 275/305 make the car understeer? I thought that was more for getting some extra straight line grip out of the MPSS.
I find with the stock tyres that the 255 up front is more than enough front end grip, don't know about with MPSS though.
I am sure you will have done plenty of research, I know Litchfield absolutely love the MPSS on the GTR but I think that could have been after he failed to buy a container of the Dunlops when they wouldn't sell them to him as they have a deal with Nissan.
I also think quite a few people who switched from stock to MPSS did it when they were right at the end of the life of the old tyre so obviously going from a tyre thats down to the canvas to a new tyre will feel amazing.
Look forward to your impressions of them, get full geo and ARB adjustment as the softer non runflat sidewalls will effect that also.
Anyway, thats just my ramblings on the matter. I don't dare to post anything on GTROC about tyres, people go nuts.