I made a couple of mods to one of my ol weber kettles. The damper blades got bent when I tryed to make it digest some lump and wouldnt choke the fire completly so I welded a ring to the damper blades.
The stock fire grate let to much charcoal fall through so I covered it with a piece of 3/4x9 expanded.
Made a ring to hold some charcoal for low-n-slo. Along with some 6" pieces to allow more air under the charcoal and help let the ashes fall through.
A new cooking grate.
I'm to cheap to buy a performer so I emprovised. I also made a tool to scrape the grease and stuff with, an old hoe that I ground to the same radius as the kettle and a log / charcoal lighter. I stick the log lighter into the air supply on my bbq to get it started also.
Its all tuned up now and I can get well over 12 hours cook time from 1 load of charcoal at 225*. Figured I might as well have a snack while I waited for it to burn out.
A butt I cooked about 6 months ago on another kettle.