Anyone know what the cruise and top speed of the 350ss is with the 496HO engines (420hp I think)?

56-57 MPH top end GPS. That is on a total option 350SS with thru-hull. I think it has seen 58 GPS when new with a light load and little gas. Cruises nicely around 33 - 35 MPH.

Knot-4-me - How is the boat in rough water and crossing sizable boat wakes?

Boat rides well in rough water. As Knot says, most of the time we cruise around 30-35 mph, probably running around 2900 - 3000 RPM there and it is pretty much the most efficient fuel burn position. The boat is on LOTO, on rough weekends we just drop the tabs a little bit and it runs great in the rough.