Adding on firebox

That unit pretty much IS a firebox. I saw one set up at Mendards...that little smoker there, right next to the Smokin Pro.

The firebox on the SnP was the same size as that little smoker!

I'd say it would be more trouble than it's worth, as you would still end up with a very tiny smoker.

I do love Craigslist though!

Lowes sells these little drum pits that are perfect for addon fire boxes... however, as Bman mentioned that is still too small for your main pit IMO.

But I was gona get one of those small Lowes drums for a buddie of mine that I got him a Great Smokey Mountain stand up smoker I got off Craigslist for only $35!! I would side box that one in a minute!!!

I think that is one you can technically add a firebox too. Just check the right side of the unit and see if it has the football shaped cut out area. If so you could add a box. However it might run realy hot since the main chamber is so small.

If you do have the football knock out be sure to read up on the do's and don'ts of knocking it out. Having a 2x4 to support the area you are hitting with a hammer is a must! Also if you can get to a dremel with a cut off wheel it works well to pre-cut the small welded areas a bit. Other than that a phillips screwdriver and a deadblow hammer are all you need.