Buddy of mine wants to sell me his Maxxis Carnivore 31 x 10 x 15.......(cannot buy these retail).....to put on my 21` X Live Valve. Therefore ending this battle in my head of 30's or 32's. BUT... One tire has a plug in it. How much faith should I put into a repair? Plug/patch, Slime......gonna run stock wheels. 100 miles on the Carnivores.......?