Tom...
Smoked corned beef is pastrami..sort of. Pastrami has a slighty different mix of spices and is cured and smoked.
I make it all the time by buying the corned beef at the supermarket. Throw the seasoning packet away, soak it for a couple of hours, apply your pastrami rub and then smoke like a brisket flat. I choose to cook mine to a much higher temp than many. I take it all the way to 180-190? or so.
Here is a favorite recipe from RandyQ....
Pastrami
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
PREPARATION:
Soak corned brisket for 2 hours changing water twice.
Grind peppercorns and coriander seeds. Add remaining ingredients.
Rub this on the corned beef brisket.
Wrap and let sit overnight.
Slow cook brisket at 275?(uncovered) for about 1 1/2hr./lb.
Meat temps need to be near 185? or above.