I wrote to Smartpartz the same night I posted here. Here is the reply I got from Smartpartz:
"Drill the hole within a 1/4" of the original hole and there should be enough movement to rotate the baffle a very small amount.
You could utilize the original hole but then if you decided you did not like our baffles for some reason you would have to secure the original baffle with a screw and a nut.
Also, using a little bit of WD40 upon reinstallation on the baffle sometimes works wonders.
The slashdown baffle does have a slight bend towards the end.
Hope this helps.
I wound up using the original hole on the baffle, but that required removing the small piece of metal that's welded to the inside of the baffle that had the original threaded screw hole. I just took a flat blade screwdriver and pried it out a good ways then braced the screwdriver against it and used a hammer to knock it off. Then I could insert the Smartpartz baffle and line it up with the original hole. Of course, this ruined two $35 baffles in case I decided I didn't like the Smartpartz...
It was still a very tight fit in the pipe and I took their advice with the WD-40. I had to use a file on the original baffle to get the Smartpartz insert to sit flush against the end. While inserting it into the exhaust, I had to use a pair of pliers to push the baffle in and position it so it lined up with the hole in the exhaust. I used a small mirror to help me see the screw hole on the back side of the exhaust.
I got it installed yesterday and it's been rainy and windy here since then, so I haven't had a chance to take it for a test ride. Revving it up in my garage, it seems to have a lower growl than the original baffle by itself. I've tried the Cobra Quiet Core baffle and didn't see much difference over the standard baffle. The Smartpartz seems like it's much lower pitched, but I need to take it out for a ride to really know how it will perform. I'll post a followup as soon as I do.
PS: Be sure to use locktite on the screws if you do anything to your baffles. Those pipes vibrate a lot and you'll eventually lose the screws if you don't. I lost the tip on one of my pipes that way. Another $35 lesson...
Last edited by VSJ725; 02-11-2010 at 12:52 AM.