was thinking about putting corsa mufflers on the boat,will I be loosing any speed?corsas web site says no, twin 496 boat.

I took mine off and didn't notice an increase. sounds a lot better w/o them though.

I have four like new ones on the shelf in my basement I took off my cigarette when I got it. Ill sell them cheap if your interested.

If you get the proper model Corsa muffler, you should be fine. I added them to my boat and I really like them. My mufflers were originally on a Formula w/ 525's, I want to say they are either the 6" or 6.5" model. I noticed no difference in performance and call me crazy, but I really like the sound of the boat better w/ the mufflers.