I have a 2005 sportsman 700 and my buddy just took off the wheels on his 2016 rzr, Question I have is there a wheel spacer that has a fatter stud on it. My studs are too short and much smaller in diameter

 

Should be able to contact any good wheel/spacer vendor and get a set of sportsman spacers with RZR studs. Believe the old studs are 10mm and the newer RZR studs are 12mm diameter. That or check for longer studs (like off a newer Scrambler/Sportsman 850/1000). The rim holes will be a bit bigger but should be fine once torqued down.