Unique question - Alternative to a permanent firebox?

I've been considering adding a firebox to my propane cooker. Got some good feedback here (http://www.bbq-brethren.com/forum/showthread.php?t=115810).

But I've achieved great success with gas. Part of it's the steady temp I can get. Part of it's the way my homemade cooker works. Its small diameter stacks, good distance between the 1" pipe burner and the cooking surface, and very thick steel angle deflector covering the burner, blocking any direct heat, and sizzling off drippings make for some incredible BBQ. I even get a smoke ring. I've done a 140 pound dressed pig to perfection (17.5 hours at 230ish).

But I love this game, and I'm a believer in the wood smoke testimonials. I've considered adding the firebox as an alternative. I tried using chips, both soaked and not soaked, and my heat's so indirect that they don't get hot enough to ignite them. I'm also leery about combining smoldering wood or coals and gas within the same chamber.

But here's an idea -- why not have a firebox that doesn't screw with the composition of my cooker and that adds smoke during just the critical first hour or two, for flavor? I understand the first ascent to temp is the only time smoke gets really absorbed, anyway. Then go to gas for the heat control and ease it provides over many hours? I'm thinking of cutting a round hole in one end of the smoker and running a flue through it from the stack of a small, portable smoker grill. Then, I could burn coals and wood of my choice, kissing the meat with smoke.

I'll eventually get a second BBQ trailer with an offset firebox and plates creating a reverse flow. Like I said, I'm hooked. But meanwhile, this sounds like a fun and possibly unique project that could yield some tasty BBQ. Any thoughts? Here are some pictures of my cooker...



http://1.bp.blogspot.com/-ChykDi9TDsg/TlJ8v6A8pUI/AAAAAAAAA00/A3YPSr6whPA/s1600/IMG_4309.JPG

http://1.bp.blogspot.com/-sPi_MXwJ_m4/Tkks0RzZLKI/AAAAAAAAAzM/62stC1xYYTg/s1600/IMG_3842.jpg

http://3.bp.blogspot.com/--bEiGecKPDE/TkksrofapLI/AAAAAAAAAy0/X5gF8lqDfQo/s1600/IMG_3944.JPG

Thanks -- that helps greatly. I just bought an after-market (meant to be added onto the side of their smaller smokers) firebox at Lowes that should weld right onto the side. I can experiment too. I'm nervous about using it at the same time I'm running propane, though. Any thoughts on that?

Good points -- clarification here...

I'm getting really comfortable with my cooker, and I'm thinking (as suggested) about running a fire throughout the cook while burning gas in the main chamber. I think it's vented well enough underneath to remain relatively safe if I had a snuffed burner.

No thin skin here -- no worries. Clarification -- I'm not worried about the LP tank. I'm cautious about the burner going out, the main chamber filling with gas, fumes entering the firebox, and it all igniting at once with the introduction of oxygen, such as when I open the top.

But good venting and a protocol of checking for flame every time before opening the door would be preventative, I think.

I have to hunch down and check every time I open and shut the top, or adjust the gas. Mine's finicky. But my therm starts dropping right away, and if I miss that you can smell gas.

Then I read a post somewhere else describing a guy's experience getting burned (bad) when a gas firebox starter filled the box and then the cook chamber with gas and blew two doors off when he tried to "relight" an "extinguished" fire. I think my situation may be more manageable -- just no newbies or uninitiated near the operation unsupervised...

Look for pictures of my mod in a week or two!!!