Well, let's not be too emphatic here. There were a lot of failures with the 14" Marathons, and many of us, led by me, complained long and loud. And I still think that the 14" Marathons are close to being overloaded. But it has become apparent that the failures may have been due to cheap Chinese valve stems, rather than poor tires. Once the wheels are equipped with decent valve stems, I'm not sure that anyone else's 14" ST tires are better.
My solution was to move to 15-inch Marathons, and I've been completely pleased with them. And the question of "will 15-inch tires fit if you don't have a lift kit?" was answered in post #8 of this thread,
http://www.trailmanorowners.com/foru...ad.php?p=50343
in which we discovered that the question of fit depends on the amount of clearance above the tire - the axle manufacturer suggests that the only thing that matters is that you have 3 inches of clearance above the tire to allow for suspension movement.
If you take the cover off the wheel well, and measure the vertical clearance above the tire, and find that you have 3 inches of clearance, then you can move to 15 inch tires. If you have less than 3 inches of clearance, then a 15 inch tire may not fit, in the sense that if the suspension flexes to the limit, the tire could hit the top of the wheel well.
So if you are going to replace the tires, you can put on 14-inch Marathons if you change the valve stems to metal. Or you can change to 15-inch tires, if there is 3 inches of clearance above the tires. Or you can change brands (Kumho, etc).
Bill