After a few problems with a generator install in my DayDreamer 11 years ago I was very specific with my tech who installed my genset in my new Champagne 38EL. He has done a great job.
First off I made sure all fuel and power cables that pass thru holes in body and metal parts were insulated very well to keep vibration from doing harm to cables of fuel lines.
Extended stay tank can be set outside and be feed directly into the low pressure side of inside piping.
I purchased a piece of plywood and a sheet of silverside hard foam insulation and cut both to fit to give me some sound and heat proofing. This shelf gives me storage space above genset box housing.
This photo shows where I tied the extended stay line to the factory piping.
Bottom two photos show where dealer tech tied my genset to factory piping and fastened tee and lines to back wall.