lionel speeder

Hard to say, the motor is larger in the PCC, so it depends on the speeder and what board it has.  This board from an older TMCC model will handle the single motor just fine.  This is the same as the ERR Mini-Commander 2, and I've used it in a number of single motored units.  Lionel actually used the same board in the HHP-8 set engine that had two small motors, but pulled four cars in the set.

the board is from the current tmcc speeders and looks identical to the mc2.

Should be fine in that case.