I would run map 5 starting out with about 25-30% E85. Do some datalogs and check out your fuel trims after you do a couple of WOT pulls. If the trims are low, add more E85. I wouldn't jump into too much E85 and then find out the fuel can't keep up causing issues. So 25% E85, a couple of WOT pulls for autotune, datalog, see what others think, then adjust E85 accordingly.
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