Will the XCT's go through the same kind of mud and stuff like my stock 489at's will. I need a good trail tire, but do some pretty good muddin sometimes. Are these good? Should I use the stock size?

You would be suprised what they will go through. The power and ground clearance of the Scrambler plays a major role in its mudding abilities, even the 2 WD model. I had them on my Sport, and it would go through just about anything.

my friend's got them on his scram 400 4x4, but for some reason he cant get through the mud or water because of his belt slipping lmao