This is the reference I use to determine the maximum cure per gallon of water:

24 lbs. per 100 gallons of water.  

That is 2.4 lbs. per 10 gallons of water.

That is .24 lbs per 1 gal. of water

.24 lbs x 16 = 3.84 oz of curing salt at maximum cure w/10% pump (which is ave. pump with seam leakage).

Per tablespoon, there is about .88 oz. in a level tablespoon of curing salt.

3.84 ÷ .88 = 4.36 tablespoons of Cure #1 (to be safe, round down to 4 tablespoons).