Can the optional lead set for the single ended P6960 be used on the P6980?

Can the optional lead set for the single ended P6960 be used on the P6980?

Yes, you can pass differential signals through the data channels of the leadset, but only single ended clocks/qualifiers since the minus side of these signals are grounded on the leadset board.  

There will be up to 0.5" of skew between the + and – sides of the differential signals, as the traces on the leadset board are not matched in length.