I have a DG Type II silencer that I'm not using. It is supposed to fit all Scrambler and Sport 400's from '94 to '03, with stock pipe. I'm sure that it would fit any pipe that is able to be used with the stock silencer, also.
I know that you're thinking DG!!!? Yeech!, but when I had it on the '01 Scrammy, it really made a noticable difference across the powerband.
I had about 4 hours on it before I removed it. I took it off because it does not have a spark arrestor, and I'm a little paranoid about running without one. It sounds good - maybe a little loud, but good - and is much lighter than the stock silencer.
Paid $85 for it last year on Haydays weekend. I'd like to get $45 for it. At that price, I'll pick up the shipping. Even polish it up a little.