e85 or stay with pump gas

I'm no E85 fan. But it's difficult to blow up an engine by being too lean on E85. We took our 500" wedge with a single Dominator to another dyno before we got our own. The first pull on E85 it made 680 HP.

Could not believe my eyes. "What a piece of ****!" I said in a huff.

The dyno operator looked at me funny, "You just made 680 HP! Why are you calling it a piece of ****?"

"Because it should be making 800 HP," says I.

"Well you aren't going to tune another 120 HP out of it," he responds.

We needed about 8:1 Air Fuel Ratio. So the day went like this, as we forced more and more fuel through the carburetor.......

12:1 AFR, 680 HP, exhaust gas temperatures 800-900 degrees.
11:1 AFR, 760 HP, exhaust gas temperatures 1,000 degrees.
10:1 AFR, 845 HP, exhaust gas temperatures 1,100 degrees.
The intake manifold has ice forming on it.....and we're out of dyno time.

So I guess the dyno operator was correct. We didn't tune another 120 HP out of it.......We got another 165 HP out of it that day.