Hey Saillfish,
Your Cougar looks great. Clean install. I will be using a KingTech K-85 in my Cougar as well. I was debating building a little bigger fuel tank but would prefer to use the stock tank if I can make it work. It would be so much easier and avoid me having to cut the ducting to accommodate a larger tank. The K-85 is a little thirsty and just concerned about the stock tank being just a hair too small but don’t know. What kind of flight time do you think will you be shooting for? I imagine most of the time I will be flying at 50-60% throttle.