Here's the brine/cure recipe I used, except I TRIPLED IT because this was a huge loin, requiring a good amount of liquid to keep it covered.
8 cups water
3/4 cup coarse kosher salt
1 cup brown sugar
4 tsp Instacure #1
1/3 cup maple syrup
1 sprig of rosemary
I soaked the loin in the cure/brine for 5 days, turning it over every day.
After five days, I soaked it in cold water for an hour, then smoked it with peach on the rotisserie, aiming for a cook temp of 220. I removed it when the internal temp hit 145-150, then allowed it to cool overnight before slicing thinly.
FYI, I placed the charcoal baskets in staggered positions, so that the center of the loin did not get done before the ends did (this loin pretty much filled the rotisserie, end-to-end).