Gearing up for E85 here and dropped in a Walboro 535. I did the FPCU bypass that's on the Concept Z wiki and haven't had any issues so far.
I replaced all the other fueling components with new OEM parts (damper, regulator, filter). The only thing I've noticed is it takes an extra second or two of cranking to get her running. Currently still on 91 Octane. Tune is scheduled for next year :(