More Top Speed

I have an 06 rhino 660 SE that is stock, It is legal to license atv's and utv's here in South Dakota, so I was wondering what were the best things to do to modify my rhino for top speed, I don't really need stump pulling bottom end so If a clutch kit would raise it that would be fine. I'll spend $500 on motor mods, I'm gonna put 14" Motorsports Alloy wheels and BFGoodrich All-Terrain Truck tires on it. Thanks

My cousin's Husband put a CDI, Sheave, and a K&N filter on his stock SE rhino and it runs about 56mph. No exhaust or any other mods.

My Rhino runs about 53mph with just a CDI.

I installed a black rhino CDI and got the top speed to just under 50 MPH. BUT, it wont stand those speeds for long periods I don't believe.