Cowl Cutting
Do yourself a favor... Cut BIG.
This is always one of my most painful decisions. I just built this gorgeous plane, and now I have to cut it up(!) But it seems like every time I try to cut away the least amount of cowl, it comes back to haunt me. Now, I just accept the fact that an engine needs to breath, and cut large enough so that I won't have to enlarge it later.