David, welcome to the group.
Smoking times can vary so much. Some people cook at medium temps and cook in a few hours and some people go as low as they can and stretch the time out 20 hours or more to get all the smoke penetration they can.
I agree with Bob-BQN that you let the remote thermometer tell you when its done. As for Steven's recipe, I've read enough of his material to know that he says Grilling is not an exact science where food+ temp +time= consistent measurable results. Live fire cooking has some less predictable variables that make it more of an art than a science sometimes. The more we progress from grilling to barbecuing the more this is true.
When I got Steven's book "How To Grill" I was confused that more recipes didn't spell out whether to cook with the lid open or closed and disapointed that more recipes didn't include the internal meat temps for doneness. But I knew how to find out proper meat temps elsewhere. No big deal. The lid question is one of the things that sent me to this site where I learned about lid use and much more besides.
Still, I've never been more impressed with any cookbooks than I am with Steven's. Steven's cookbooks didn't answer every question I had about grilling. They got me thinking and made me come up with even more unanswered questions than I had before.
I'm glad of that, otherwise I wouldn't have discovered this website.
For me, its been the combination of Steven's books, this site, the TV show, meeting Steven in person, and selling grills for a living thats been a great learning experience.
My friends probably think I'm in a barbecue cult but who cares. I eat better than they do.
I sell grills for a living, what can I say? Of course I'm a fanatic.
Anyway David, I'm sorry you were disapointed with Steven's recipe. Hopefully there will be many more recipes in the book that will make you feel the book was worth the money.
I'd like to suggest that once you've smoked your Turkey Pastrami, please post your smoking time, temp, meat weight, starting internal temp, and finished internal temp or post whatever you feel was left out of the original recipe.
There is a great post called BBQ Log with a great format for documenting barbecue conditions and results. Posting pictures is always appreciated too.
For anyone else here whose done this recipe, do yo recall what your smoking times and temps were? I haven't gotten around to trying this one yet myself.