So I just received my Berk exhaust and took a look. It looks like only the tips need to be trimmed. The tip can be slid about as far onto the pipe as you want, it's tight, but you could it. So I'm not really sure the pipe needs to be shortened? Not really sure what that would gain except not having it protrude into the tip? You can't really see it. OTOH the tip has the least tolerance to trimming. I would imagine you would want to leave some of the slits so the clamp can squeeze. But the slits are only 1" deep so I wouldn't be comfortable taking more than 1/2" off. You could make deeper slits but that is lot more work for the DIY'er and might get you another 1/2" at most.
I may have to get everything hung before I know how this will work out...
