Bags Splitting???? WTF

Ok, I'm not sure if this is the right forum to put this in, but it looked like the closest thing for my question.

I bought a buddy's Magnum last year. As soon as I got it, I checked over the suspension and decided to replace the front bags, because they were splitting apart at the bottom (they were 5 years old). A few months ago, I noticed the rear bags were doing the same thing, so this past Saturday I replaced them as well as changed the front brakes. Well, as I was changing the brakes, I noticed that my 1 year old Firestone 2500s are splitting apart again at the top and bottom around the mounting rings! I live in Texas, so I assume maybe the Texas heat is doing it to them, but I don't know. Is anyone else having this problem with Firestone bags?

And, before someone suggests: No I can't use Dominators, because they will rub on the suspension components. This was the first kit the Ekstensive ever did on a Magnum and the room is a little tight.

Thanks