I had a similar experience running WMO (from multiple unknown sources) in my 84 6.9 IDI. Lots of blue smoke, stalling and surging, and very unpredictable. I abandoned the project and, thankfully, after hooking a fuel can with a high concentration of Diesel Kleen up to the IP, I was able to get the truck to behave normally again.
I had a similar experience with the same fuel in an 83 Mercedes 300SD. Low power and lots of smoke.
I was using a centrifuge (5-10 passes) and mixing with 10-20% RUG. I could never get the truck to play nice with it.
I have no doubt these trucks can be made to run well on W85 (or what have you) but it didn't work out well for me.