Hey,
I was just wondering about some exhaust options. I got my 96 303 with 502's with the Silent Thunder box removed. The previous owner gave me the box (which is in great shape), but I have been hesitant to put it on. I mostly like the sound of the straight exhaust, but here in Cape Coral, sometimes it fun just to canal cruise. But, it's a little obnoxious cruising the canals with a pair of straight piped 502's behind me. So, I was wondering about maybe some muffler options instead. Any suggestions?

Some switchable mufflers would probably be your best option. They take a lot of bark out of the exhaust.
Drew Marine Shotguns also work pretty well. They are automatic and open more as you increase rpms.

I have the silent thunder on my 242. I personally love it. I get the bark at start up and a slight rumble at idle. It sounds great and isn't obnoxious like my donzi. They each have three place but I like being able to pull in somewhere and not have to worry about upsetting anyone. I get the straight pipes like my donzi but anytime someone wants to talk from another boat I have to shut it off. If I were you I would try the silent thunder and see. You can always open up the bottom like some do to make it louder when running.

Is that 93 db with the water drains in or out?

My silent thunder is cut with 2 tips right above the drive. I love it. Just enough attitude at the dock, nice cruise that isnt loud at all.

On my 353, the box had issues after a year or two so we installed silent choice along with muffler tips. Happy ever since (after I removed the rpm-based actuator module that flipped the silent choice on and off continuously at around 3000 rpm LOL).