74, your settings look OK. Gregg's right, especially on smaller cuts (believe it or not, 7 lbs is right on the line of a "small" cut). I tried to smoke a 4 lb corned beef flat one time, an it took 11 hours!!
I never smoke flats, so I'm no expert on timing for them. With full packers, I normally see 1 - 1.5 hrs/pound. Always allow on the high side of time; you can always rest it in the cooler, double-wrapped in HD foil, with towels covering it.
Are you using any drip pans in the smoker?