Played with a few ideas over the last year to help make my Small BGEs better for my needs.
I have made mods to the standard firebox, purchased Hi Que fire grate, put spacers under the stock firebox and even made some mods to a Medium BGE firebox to make it fit the Small. Some worked better than others. The Modified Medium firebox worked the best but took some time to cut and miss cutting or breaking it is a risk.
A couple weeks ago I purchased a Kamado Joe Jr. The price was to good to pass up. Last night I took the firebox and ring out of the Jr and compared it to my Small BGE parts. The KJ Jr parts were a little larger in diameter but made a perfect fit in the Small BGE. Still enough room to allow expansion when heated. I know the molding process is not perfect and there is no way to know if this will hold true with your Small Egg.
The KJ Jr firebox is designed with a larger lump grate and larger air intake hole. Because of this it also has more room for ash. These were some of my issues with the stock BGE firebox.
I did some test cooking last night and it worked fantastic. I also swapped out the KJ Jr lump grate and dropped in the lump grate from my Large BGE.
This really made it a grilling machine.
I only filled to the top of the firebox and I used some of the Williams Sonoma Coconut lump. Honestly, the lump is far from great stuff and I will try with OO or some other good lump next weekend.
Cooked chicken and sausage on the raised Woo at 300. The fire was very even with less hot spots. Temp was easy to control and when I needed to sear the temps jumped from 300 to 550 in just a couple minutes. I even got a flash back a couple times...never had the power in the Small to make that happen before.
Really reacted and cooked like a cross between my XL and Large. I made my test cooks with the KJ Jr box and fire ring but all you really need is the firebox as the BGE Small fire ring will work over the KJ box just fine.
I believe this step child will cook very similar to the new Mini Max but retain the taller stance and larger capacity of the Small BGE. If you have a KJ Dealer local they might be able to order you a Firebox. Fred's BBQ on the web is my next call as they seem to always have a good stock of everything.
Hope you enjoy this information as I'm very happy with the results.
My next post will be a steak and a rack of lamp pops also cooked last night.