The Lionel 6-8007 is a DC powered locomotive: https://www.lionelsupport.com/...ents/70-1050-250.pdf
I believe the Lionel 8902 is also DC powered.
For what it is worth, Lionel O Gauge is traditionally AC powered - the DC powered units you have are oddities. They are easily converted to AC power by the addition of a bridge rectifier. If that is of interest, let us know and we can get you going down that path.