I don't have Dyno Sim but I do have PipeMax. The PipeMax numbers are fairly close to what we see on the dyno. PipeMax does say that I need .866 valve lift and I'm not quite there. But that is just a limitation with these heads.

PipeMax is recommending a 2.125 header that is 29 inches long with a 16 inch collector. The original PipeMax calculation that I did a few years ago told me 2 x 34 inch header. It will be interesting to see what difference it makes.