I had modify the fuse quite a bit to except the OS .91 Surpass and the fuse mounted main gear. I moved the firewall aft 3/8" (this required a new taller firewall) and I had to build up the bottom of the fuse sides to accomidate the landing gear mounting block. I cut the "cheeks' off of the sides so that I could build up the cowling from balsa blocks similar to a Super Sportster.