I removed the silent thunder box, seals were leaking and it had some cracks in it.
I know some folks like the open exhaust but it was too loud for me.
Got these from GGB, nice stuff well made, unique baffle design.
Easy to install, worst part was getting to old transom rings of the hull.
The exhaust hose was stiff enough that the new muffler nipples pushed right in, I didn't need to take the hose or risers off to install them.
I haven't had a see trial yet but they should take some volume out of the exhaust, gotta put flappers on though

What do these go for, I'm considering something like this too.

I have them as well, they sell for 399.00 each canadian plus the ride. Good product, made by Graham him self in Canada. One man operation. No mass produced crap B.H.

WOW, I didn't realize they would be that much! They do look nice though.