I really hope youre joking or Im reading that wrong...
I gotta say with all the e85 stuff ive messed with, I really dont think those 42.5s will be enough... that being said, they could be but youre not gonna be able to go any further really on e85 with anything less than 60s... unless youre keeping it under about 3000rpm for the rest of its life...
honestly if you are not tuning it yourself... or having a local guy do it... and having to pay EVERY time for a tune...
I would recommend not going ethanol...