Kevlar, I'm sorry that hearing facts every now and then crushes your ability to do things you can't do with your truck. You asked why he didn't run it outboard all the way down the truck, I told you that if he wanted to run his emissions equipment like cats and mufflers, there wouldn't be room, and he would have to dump before his wheels, which works for the case of his cutouts when he just wants some wide open off-road exhaust, but not for when he wants to DD it. Whether or not I told you that wouldn't have changed any of that.
Just like the thread where you wanted someone to tell you that the stock manifolds are good and all you needed was a catback to make big power. It wasn't until someone else showed up to post pictures to show you how bad the stock manifolds were that you shut up.
And just like the header buy. You wanted to know why no one produced it for cheaper, I said you guys are seriously underestimating costs, told you what another header company said they would make the headers for that I had contacted myself 8 months prior, and then the OP came in and even verified everything I said with information he got from Al.
Stop confusing fact with opinion. No amount of creativity is changing any of that stuff. I encourage anyone who wants to make a set of headers to do so, but I also remind them that it is a lot of work, it is hard to do, and as this thread illustrates, space is a hell of an issue, so you have to be damn creative to get anything done. I tell people things like this because I don't want them to jump into a project they are going to get in over their heads with and lose money on. It is much better for people to stop and take time to consider everything they do and plan carefully beforehand, even if it stops some people from trying some things. If my posts EVER stop someone from trying, it is someone who wouldn't have succeeded, and wouldn't have had the guts to push through a project when it got tough anyway.
For your other consideration you are talking to, you CAN make it between the frame with a pipe of the size the OP is using, but you have to get creative with the pipe, which means you may have to re-shape it a little. In other words, you oval it out a bit. A 3 inch body lift would give you another half inch or so of clearance though, so you may be able to fit the pipe through without a problem. Even without the lift, this size of a collector might squeeze through, but I would worry about interference problems without solid motor mounts. Another possibility, since long tube headers aren't going to line up with factory exhaust anyway is just to run the primaries down between the frame and put your collectors much further back, but then you will have to lift the engine to install and uninstall them. This, however, is not that uncommon a thing to have to do for anyone who has put headers in an old muscle car.