Yes, there are internal flaps to prevent reversion.

[QUOTE=mittens;3149320]mine look like this ont he out side



Mine has the full pipe (big hole )and you can see the butter fly flappes on the inside.

the picture below has the same outer flaps, but the picture where the flap is open, it has has a smaller hole, mine does NOT look like that. that is a muffled tip, DID YOURS LOOK LIKE THIS OR NOT? mpally?[QUOTE]

Our old tips looked liked the one in the bottom right in your picture, but I think there is an additional set of mufflers on the inside. You can't see through the old tips. I can post a picture of the old tips next week when we are back at the lake.

Yes, all we did was have the tips swapped out, not other changes.

but did you have mufflers in you tips? or just the stait through stock tips?
sorry to be suck a pain just want to be clear.

There were mufflers in there.

OK thats what i though. i gott o find someonen that had mine and then swapped

I've used the Hardin Marine angle tips with the internal flapper. It's their new design that doesn't make any noise. I hated them. The use a waffle type back plate which I feel restricted my exhaust AND changed how it sounded. Maybe not on a stock engine or switching from mufflers would it make a difference. The other thing is that the rubber gets blown back and will eventually stay that way. I was always nervous that if water went up the tip they wouldn't shut flat. The tip itself is nice. Just hated the flap design.
I would go with the Dana peices and if the flaps ever do burn out you can replace them without removing tip.