With my mods and the stock convertor with nittos and a well hooking track?

 

I would say at least a 2.0 60'. Hell, if I can get a 2.2x 60' on the budget Kumho's and a crappy track, you will surely do pretty well with the Nitto's. From what I've heard, talking to ppl around my area, Nitto's are more inconsistent than they'd like. I think, if you're planning on ONLY using the Nitto's for the track, get ET Streets instead. But if you wanna run these on the streets (won't last long) then go for the Nitto's indeed.