I have been reading about that. The max bomb load of p-38 L was 4,000 lbs. Not ofton done due to range in the pacific. Internal fuel in a 38 was often not enough to get to the target and home safely, thus this was uncommen but by no means not heard of. Was used in ground attack supporting grunts...
I am talking about the 4 1000lbs or 6 5000lbs. I believe the 2,000 lb were rare there are pictures of them carring them.