This has been a very informative discussion! Thanks for all the replies, especially TurboTech. Love seeing Turbotruck07's engine pics. Would love to see more on that.

 

I just cut the flanges off the manifolds and welded 2 1/4" pipe on for cross over .. There is a slip joint that takes a band clamp at flex. It honestly only took a couple hours with a handfull of J bends to complete. Here is a good example of what stock manifolds are capable of..
https://ls1tech.com/forums/forced-in...lsx-notch.html