Anyone know these guys? They seem to have a package for the 172 based on an auto/marine V8 engine.
https://corsairpower.com/questions-answers/
Might be an option for the RV-10.
The engine block is a marine version of the General Motors L series engine with 2 decades of proven reliability in everything from production muscle cars, HD trucks, boats and industrial applications, modified internally & externally for its aircraft mission. A few differences include internal changes to the internal lubrication system to prevent oil pump cavitation during maneuvering and uncoordinated flight; elimination of several potential single point of failure components; alternator capable of providing power even at prop wind-milling speeds; complete redundancy of fuel and spark delivery systems, to name just a few.
https://corsairpower.com/questions-answers/
Might be an option for the RV-10.