I guess I should've been more clear John. I was using the mounts for the .046-.061 engines. Even though the bolt pattern is the same per Tee Dee and Norvel, AP, Stels, Va, etc. they make different mounts for them. This is mainly due to the case width. The Norvel mount appears to be identical to the Dave Brown mounts but it seems to be harder. I found this true with an older Aristo Craft mount that I also have. What I'm starting to discover is that these mounts regardless if they work are not the ideal choice for combat planes due to their inability to take a ground pounding. I do feel that drilling and tapping the plastic is the better route to take. On the models that I already have, I will try this. Some models I have already started to convert. Some of the models have a lite ply box construction for a fuselage. The front firewall is 1/8 ply with blind nuts behind it for fastening (typical). I generally wrap the box with fiberglass after construction is complete very similar to the older Goldberg models like the Jumping Bean and Lil Satan which had the box like configuration on the nose. I've opted to go with a arrow shaft fuse eliminating the heavier wood box fuse and I use a solid wood block on the nose on which I use aluminum mounts to hold the engine on like a profile. Ken