Hey Sherm,
In the NHL history, when the visiting team has a 3-0 series lead, that team is 21-12 overall in game 4, and has gone on to win 32 out of 33 series. That bodes well for both Det and Pitt over the next 2 nights.
Incidentally, if the team with the 3-0 lead plays game 4 as a Home team, the record is 76-40 in game 4, and 115-1 overall to win the series.
Does that help?