Here is about the best resource I have seen for making your own corned beef and/or pastrami...... http://www.randyq.addr.com/recipes/pastrami.htm
I have made these several times using store bought corned beef. You just need to remember to soak the corned beef for a few hours in water....changing the water frequently.
Once you do that, then simply apply your rub...I have listed one below..and smoke it like you would a brisket.
Now, I like to take mine to 195º as I do not own a deli slicer. If you only take to 165º, it will be very tough and needs to be sliced razor thin to eat.
Good luck and enjoy!
1 Corned beef brisket
2 tablespoon(s) Peppercorns
1/2 tablespoon Coriander seeds
1/2 tablespoon Onion powder
1 teaspoon Thyme, dried
1 teaspoon Paprika
1 teaspoon Garlic powder
Soak corned brisket for 2 hours. Throw the seasoning packet away!
Grind peppercorns and coriander seeds. Add remaining ingredients.
Rub this on the corned beef brisket.
Wrap and let sit overnight.
Slow cook brisket at 275º(uncovered) for about 1 1/2hr./lb.
Meat temps need to be near 185º or above.