That attic plane and a new build I take it one is up right and the other is inverted engine mounts. That’s interesting. Never seen an inverted Super Ringmaster in the Circle. Your mount rails I guess are in the same location but the engine case would be inverted on top of the mount. Now your fuel tank to me that’s the big question. It would be located below the engine mount rails, I guess you could do away with the mount rails and go with a RC type metal engine mount. That in my way of thinking would work a bit better, for an inverted engine on the Super Ringmaster! Lots of interest stuff in U Control! AJ