We,ve set up a few 496's with the new CMI kits. I say kits, because there is a lot more in the install than just boltng on the headers. It will take a good mechanic an honest 8 hours labor depending on the boat. Yes you can run cast s-pipes to below a swimstep, but depending on the fit measure carefully and talk to CMI or Fred at Trick Marine to make sure the tips they supply in the kit are the exact correct length.
Ray @ Raylar