It appears to me you said you are using a cold outside smoke generator, and sending it into your smoker. Did I get that right?? Maybe not---I'm getting old!!
If that's the case, and you want good smoke flavor, give it light to medium smoke from the beginning to about 165* IT. Then wrap it up in foil & take the IT up to 200* or 205* IT.
Then take it out and let it rest in a cooler with towels for at least an hour. Then it's time to pull it apart.
Meat will take smoke at all temps, maybe better between 100* and 140*, but if you want good smoke, make it light to medium as long as you can.
NEVER give it heavy thick smoke, not even for a short time. That can give you a bitter creosote flavor.
Also, I use Hickory all the time, because like you I like a good smoky flavor.
You can Double check how you're doing a Pork Butt, by going to the bottom of this post, click on "Bear's Step by Steps", and then choose "Smoked Pork Butt".
Bear