I am looking to hook up my silent thunder exhaust in my 242 ss , it has down pipes coming out underneath the platform. Are there any ideas about this or any diagrams out there , any info would be great . 454 not as exciting without some noise !

do you have any pics of your exhaust? would like to see down pipe set up.
if you cut through the platform it will need to patched up for silent thunder

It has the Y pipe connected to the exhaust manifolds ,can't I just cut 4" hole out the back into the platform like a thru hull exhaust ?

I see now.. it depends on the platform you have. on silent thunder the exhaust goes into the platform and out of tips. the platform acts as the muffler. you could remove platform and cut holes in transom for the straight thru-hull

I removed my silent thunder and added elec. switchable tips,, I love them.

Here was link to see..... http://www.youtube.com/watch?v=fzkLaf3kG8Y