My cam is the identical one Steve used in his build. I believe that 236 exh dur. is a typo. It should be 242. I don't have any dyno numbers. I do shift at 6400. I'm assuming my peak is around 6000. The XFI is one of comps most aggressive grinds. It was designed for the long stroke of stroker motors. They also claim it is easier on the valvetrain-especially with valve closing. I wish I had gone with their bigger 242/248 cam. I forget the total specs on it, but it seemed to be much more aggressive when I plugged it into the calculator. I would have liked to have another point of compression to run it.
That 236 is a decent cam. I have run a 6.80 1/8 mile with it and a 1.44 60 ft. This indicates I'm falling off on the top end given my 10.91 best. I'm assuming this is due to my fuel issues and not the cam. I do think wize is right about the duration. I think a 24x cam is right on the money for a 418 street/strip cam.