If my Delta 88 was a fluke, bring on the flukes.
During that same time period also owned a GMC 3/4 ton auto 2wd that run 100% on propane. What a dog that was!!!! Fuel consumption was not even close to my Olds but was better than a regular gasser.

 

My old power wagon used to get 15 mpg with a 360, running on 5 and 1/2 cylinders,The previous owner had a insta lube outfit service it, They installed to low of a air filter and he proceded to drive it in the hills for hunting etc for many miles, Ive never seen such a ridge in the cylinders when it was torn down ,brilliant me ruined it by rebuilding the engine and really didnt notice that much more go but now got 11 mpg.