MAC Straight Shot won't fit!!! Help please!!!

Ok, so I'm trying to install my new straight shot system and it won't fit!!! The steel tube seems to be about an inch or so too long. Has anyone else had this problem? I thought it was supposed to be like a 45 minute install, but I've been at it for about an hour and a half, and if I don't get it on soon, I'm gonna have to put the stock one back together before I have to be at work in 3 hours. Any help would be appreciated.

Thanks-Mike