Onan QG2800i replacement info for older Roadtrek

[honeyboy]

I’m wanting to explore changing out my 23 year old Onan Generator fr a new QG2800i Onan. There is one Onan shop about 50 miles away who say the can do It but it will cost about $6k! That’s outrageous IMHO. As I call around, I can’t get any good info on parts needed to do the swap. I’ve called Onan and, they can’t answer my questions.
1-will I need an adapter kit to hang the new 2800i?
2- which exhaust pipe should I order?
3-can I use the existing remote start wiring from old gen or do I need a new harness w hour counter?

This is frustrating not finding anyone who knows about these things.
Does anyone know a shop, anywhere who is experienced in removing and replacing the Old Onan from a 23 year old Roadtrek 190 Popular? Has any group member done it themselves and know the answer to my questions? Thank you ahead of time. I am going to cross post this to other RT groups.