Mark,
adding to the above, if your running a classic it replaces a cat but you can have a straight through section rather than having a silencer/resonator.
Not sure about ther remap thingy with the classics tbh. Anyone Know?
I can supply these sections through a friend who fabricates for both newage and classic if your interested? ASk St3ph3n or craigwrx about the quality[]
Gus