I'm going to bet that these don't work, and I'm sure there's a reason why burried in a thread. But do the LS1 BBK Long Tube Headers w/ Y Pipe work for a thirdgen LS1 application, or will they run into the frame rails? Here's a photo.

 

If they're for a 4th gen then yes, they kick out at the collectors into the frame rails

Someone with a torch may bend them inwards enough

 

And that Y-pipe isn't even close to working.

I have a link showing how a guy heat-bent those headers to work, I'm just a little hesitant about posting it. I feel like a LOT of people will have a distorted perception of what it'll actually take to make them work.

If you have a welder or know someone with one, start modding them! Making/modding/building headers is hot-rodding 101!