Propane dual fuel theisablility on a 392 international
Just wanted to pick a few brains about putting a dual fuel system on my skoolie. I have a 1970 Superior that has been converted in the early 80's. Its other owners tried their best to it up to date, but weren't exactly handy with the hammer and test light. Anyways, the bus has a 392 international motor for a mill attached to a 6 speed Allison set up in a pusher configuration. The motor was rebuilt about 2000 miles ago and does its job of getting the big boy up to speed. Here is my question-- after getting to running speed---wouldn't it be more efficient to switch over to propane (say I'm on I-80 cruising at 65MPH haha) instead of using gasoline? What engine concerns would I have---valve issue--piston scoring--etc. I've asked others locally and it seems everyone around here (mid-Michigan) hasn't the slightest.....any chimes in are greatly appreciated!!!