I would most definately brine 'em. Use your favorite brine or heres my loin brine.
Pork Loin Brine (Pork Loin = 140 IT)
1 qt. Water
1/2C Brown sugar
1C Apple cider
1/4C Maple syrup
½ T Maple extract
If you have two equally 12 lbs. freeze one, cut the other in half or even quarters and experiment. Use a brine, not a brine, a rub, maybe inject one then draw your own conclusions. All four will be good, not sure about the plain one but it should be edible. I garantee you one method will jump out and make you wonder why no one ever served loin to you like that before. The others will be good. but one will be far and above better than the rest.
Other than game, loin is about the most dense least fatty dryest piece of meat you'll ever cook. When you learn how you like it, you'll be impressed.
Me, I am very low (200 to 220 degrre cooking temp), I want a 24 to 36 hour brine as above. Then I would dry it to form a pellicle on the outside. Rub it simply with salt, pepper (I like ancho currently), papcika for color, and just before inserting in the smoker a good rub of light brown sugar.
The light brown sugar will liquify encapsulating the loin, caramel with heat till it crystalizes again (you can't really see or taste it). Its like a M&M, that candy coating holds the moisture in. Its delicious, tender, juicy, and will amaze your taste buds.
Here one with a peach glaze:
Heres a plain brined one, just read thru all the extra BS
Hope you find a new favorite meat, Bonne Chance!
EDITT:::::: Oppps guess I type too long.