ccozart09

i have a 02 chevy 2500hd that i bought abut a month ago. it has the 8.1l and 6 speed manual. i noticed driving it home that the guy told me it was a 5 speed but come to find out it was a 6 speed. this is the newest truck i ever owned so i was just glad to get it. anyway i went to put it in 6th gar and the shifter hit the dash and when i let out on the clutch it just grinds and kicks out. it never goes into gear. a few people said synchronizer or synchronizer forks bent? or the 6th gear shift fork is bent or something?? i have no idea. can anyone tell me wats goin on and if i am going to need a complee rebuild or i can just fix the problem. any help is appreciated. thanks