Here's my thread:
http://ecomodder.com/forum/showthrea...ado-11135.html
The links are temporarily down, so I attached them here. The framework is steel strapping from Homey Depot (just steel strips with holes). It is fastened with 1/4-20 screws, fender washers, and spring nuts.
I did the first version of my grill block and partial belly pan at the same time and saw a 3.5% improvement (no A-B-A, but I compared data with as few changed variables as possible).
Mike