I have TTI headers back to TTI head pipes with servo controlled cutouts grafted onto the head pipes, then the exhaust runs back to Accurate Ltd. high flow AAR mufflers and out the diffuser-less Accurate Ltd. side pipes.

I took a 6" diameter 3/8" sidewall pipe and cut out some "channels" to graft into the subframe connectors. Super rigid and turned out really nice. It was A LOT of work, but I've seen what you took on with your Cuda, so I know you can handle it. Here are a couple of pics.