Unless they've changed the Swamp Light's rubber compound, they are really soft and wear out relatively fast. My dad has a set for his Big Red side by side, he only uses them in the winter, because he uses it so much for farm work in the summer that he'd wear 'em out too fast.
Vampires are the best you can get, and I'm pretty sure that they are still available in 25-13-9, because I plan on putting some on my 6 wheeler. You will not be dissappointed if you go with Vampires. I just recently put a set on my Big Red, and it'll out mud anything else I've seen.
Don't forget to mount the front tire with the tread in the opposite direction of the rears!
