Well, thanks for everyone who posted. Even though my remote thermometer
isn't working yet, I used the old school "poke in the meat" style.

I started things out at 300f on the smoker.. then I noticed the temp
jump up really high. The wood in the smoker box had started on fire...
bummer.

So I got it around 275 and it didn't ignite. Just smoked. After 4
hours I checked the temp, barley 130 in the center of the roast, so
since I was done smoking I turned up the heat to about 350 for another
45 minutes or so. Caught it right in time as the sweet corn was ready
too!

When all was said and done, it was probably the best pork roast I ever
had. Had some friends over too to help me eat it and they said it was
delicious. Tender, juicy, etc. I think it may have been a ribeye
roast.. it had a good marble and a bone in it.

My question now is how can you smoke at 300 degrees without having the
chips start on fire? Should I be using the bigger chunks instead?

I am using the Walmart LP smoker (great outdoors).