To my knowledge no one currently in the UP steam program was their for the 3985 conversion. There probably is a learning curve here.
I'm told that UP still has all of the blueprints for #4005's conversion to oil fuel (and UP was blueprint crazy). I understand that #4005 was a good steamer on oil, so I would think that it will be a pretty straightforward process.
In fact, according to Bill Kratville's book, plus information from some of the "old heads", the conversion to oil burning on 4005 didn't, start out very well. There were MANY, MANY leaking staybolts in the firebox, after almost every trip. Eventually, once the shop folks, and the Mechanical Dept. men got their heads together, and got the burner properly aligned, plus added additional firebrick, 4005 began to perform MUCH better. By the time the "oil fired experiment" was concluded, many Firemen stated that 4005 became just as good a steam producer, as the rest of the coal burning 4000s. Of course, the 4005 used LOTS and LOTS of Bunker C, and thus couldn't handle full tonnage westbound trains out of Cheyenne, as she would run out of fuel on Sherman Hill, prior to reaching Laramie. The coal burning 4000s and 3900s could take coal at the big coal & water facility near the top of The Hill, however there was no steam plant there in order to heat & supply Bunker C fuel.