Using a dremel and a cutoff wheel (actually several wheels), I finished trimming back to the 3/8" line in the bottom cowling cutout for the oil cooler and the radiator. I sanded everything smooth and then refit the cowl. It fits slick as snot. I'll remeasure everything and sand or file away more in spots that aren't quite trimmed back to 3/8" at some point. I also added a bit of RTV where the pitot tube begins to snake around the airbox on the Rotax 912iS. I saw that the Lockwood RV-12iS that someone posted on Van's Air Force had done that, though it's not in the instructions. And I torqued down the #1 EGT probe.