Lower Back- #1 Good Mornings probable best, Reverse hypers, 45 degree hypers, Glute Ham Raise, Cable or Band Pull throughs
ABs- all types of situps but u need to use more then bodyweight. Hold a dumbell or plate behind your head or on your chest and do heavy sets of 12 reps.
Holding behind head tends to stress lower abs more while a dumbell on chest near chin hits uppers. (at least for me)