IIRC, liquid malt extract contributes 37 gravity points per pound. So 3.7 lbs times 37 points divided by 2 gallons yields approx. 68 gravity points, or 1.068. That will be a rather hefty beer, if that's what you were aiming for. You might try to make a 2.5 gallon batch (that's what I always did with my MrBeer). That would give you a starting gravity of 1.055, which seems more reasonable but it's not for me to decide.