Here's a guy that killed his Honda engine off the Honda-Tech forum that was running E85. It corroded the aluminuim parts in the fuel system and fed that mess into the cylinders. Wouldn't want to do that with an LT5.
H
"I killed a set of brand new RC's, new aeromotive fuel pump, new aeromotive regulator, then the motor had more issues. After a bad leak down test I pulled the head the machine shop said there was white powder (Aluminum Oxide) was logded in the valve guides. You could clearly see the white powder on the intake valves and port. So I am about 2 grand into fixing E85 damage. The butt kicker is I put the car back on Cam2 110 and it made the exact same power as I did before.
Maybe I got some bad batches from Citgo, I don't know but the damage and possibly exploding decent $ motor wasn't worth the possible extra hp. After my experience a few locals have been dropping injectors ect. They all switch back to VP or Sunoco race fuels and make almost the same power.
I would like to see that same car above ran on some 110 on the same timing."