i want to put a 1.5 or 1.75 track on my 2000 sx 600r yamaha snowmobile and i am wondering if i have to modify my sled to do that or if i can just throw the new one on?.... main consern is clearance

Are you planning on studs ?? And what is the size of the track lugs on it now ?

I have a 1.25 on my 99 yamaha 600 and that is i think max without any mods, i raised mine with 3 1/2 drop brackets, but am now having some kind of rub problems, which makes no sence, but track was loose so tighten it, hope that was the problem, have u ever had any rub issues when in deeper snow at half throttle??