The N model swingarm had a small nylon roller mounted on top behind the pivot chain buffer (which is also different). The N also has a frame mounted, spring loaded chain roller underneath the swingarm ( behind the pivot point ). The swingarms look as though they will fit either model . I have a swingarm off a T , which I am not sure if i'm going to use yet , but it is in poor condition with lots of chain rash . I think that the airbox is different in that the T model box has a hole at the back , just below the seat base , where it bolts to a mount on the frame . I believe that the rubber boot between the carb & the airbox is also different . Despite these differences , I think that either airbox will fit ( maybe with minor modifications ). My brother has a RM250T in good race ready condition that he wants to sell . I will list it with a photo soon & I may be able to bring it to CD5 if anyone is interested . I have a RM250N that I want to sell as well, but I don't think that it will be ready in time for CD5.