Does anyone know if a 121 x 1 1/4 Ripsaw track will fit a 2000 MXZ 500, and if so what studs can you use?

Yes it will, I have the same sled with the same track. Studs I have 120 Stud Boy power points 1.375" i beleive and I would recommend using power tower support nuts because it is a pretty long stud and will bend easily on pavement or and other hard object. Also High performance sells a cooler protector for that sled. BUY IT. Wish I would have in the 1st place

how does your sled hook up with that track? will it haul the skies off the ground?

Well it use to. Right know I am having a problem with bad track spin????? But yes when I 1st put it all together it would bring the skies way off the groung almost vertical on a good trail. I adjusted the limiter straps to take care of that problem. Looked cool but was no good for riding.