Bill,  We routinly install turret style terminals into both plated thru holes and into
non plated thru holes without pads on both sides.  The only difference is the style of
rollover used.  In plated thru holes, or on holes with a pad on the clinch side of the
board we only flare the terminals.  In holes where there is no pad or electrical
connection on the clinch side of the board we use a rollover to allow the terminal to
get a better bite into the board.