I'll post an update when it's done, but long story short, I and a local welder hand built an X crossover style muffler short enough to work. It's a 2 inlet, 2 outlet style. What I do is have a mandrel bend 180 go back from the collector toward the engine, then another mandrel bend 180 go back away from the engine into the muffler. You kill your torgue if your pipe behind the collector is really short so I wanted to keep it long and not just dump directly into two inline mufflers. The X crossover should give it a bit more scavenging too.I hate it when I have to revisit - especially in depth - things that I thought were completed.. Curious how you’re going to handle the exhaust in back of the headers!