This kit is a tri-fuel kit, it leaves the existing fuel system intact, and it was a requirement of mine to purchase the kit.
The only thing I did was make a temp adjustment to the gov to keep rpms at 3600 under load on nat gas. This was the first time I had a chance to utilize the kit, I'm thankful that I had it on the shelf. I was able to pivot fuel before I ever got to the point of running out of unleaded.
I'm looking at the PNG kit and don't see a downside. How do you have it hooked to NG? I'm looking at getting a 3/4" hose to run about 50 feet from the side of the house, instead of spending $1200 to get NG piped onto my patio from the attic. Are you using a hose, and if so, can you provide the details on the hose and fittings?