For purposes of a fiction novel I'm working on, I need to know if an old Grumman Goose could use fuel found at a marine refilling pier (mogas = auto gas, not diesel) instead of the usual avgas. It is only needed for one trip (not permanently) and hopefully not cause "major" damage to the P&W engines. If not, is there some additive that would temporarily make it possible for the one trip or some quick adjustment to the engine/fuel-systems? Thanks for any help.