I thought about it for a couple of days and my theory was the sock was plugged. The pump is pulling so hard that air is getting in past the rubber lines. I pulled the sender and sure enough it was plugged up. I have it back in the tank and everything seems to be running well now. I can dive the truck again and it doesn't stall anymore. Much more junk came out then what is in this picture.
So next I'll pull the tank and flush it. The prior owner said he "drained the tank", but I think I just pulled the gas out and never flushed the tank.