Calculate the 3-month futures on crude oil, gasoline and distillate if the current spot prices are $49.35, $55.11 and $43.10 respectively, with a prevailing risk-free rate of 1.25%. To store crude oil and gasoline, it costs $4 and $1.50 per barrel respectively, payable upon removal. The cost to store distillate is a constant 3% of the price. Using these futures, calculate the profit margin that can be locked in using a 3-month 3-2-1 crack spread.