Would it hurt?

[79BIG10]

On the truck I have Aerochambers dumped with megaphones (echochambers) mounted right on to the ends of the mufflers. When I mean on the ends the mufflers were used when I got them and the muffler shop had cut them close to the outlet. Now can I take them and cut the phones off without hurting the muffler? I was going to use a recip saw to get a clean cut rather than a torch which I don't have anyways. I have the Blazer setup with mufflers like this but it has about 3 inches or so of pipe coming off the mufflers on it. Those haven't been ran long or at any great length yet to tell if it would hurt. I just don't want to hurt anything by cutting them off and later adding some pipe to make the bend down like they need.