I asked a question about an engine upgraded to higher horsepower (assumed it was an engine swap). Evidently the engine in question on a plane for sale is the original 582 the plane had however the cylinders and related hardware were replaced with 670 parts by Rotax Rick to make the 670 power plant. Essentially it is a big bore 582 with the original serial number for the plane. My question is what have those that have the "zipper kits" on the 9 series, or bored out engines done as far as paper work? The guy selling the plane is telling me his A&P looked over the paperwork and said most don't even upgrade the paperwork since it is the same engine same serial number, but if you did it would just be a 5 hr phase 1 fly off and file the paperwork. Opinions?
Mark