I hate to sound like a broken record, but E-85 is NOT METHANOL. It is nowhere near as toxic or as corrosive as methanol, and alcohol is never alcohol. There are VERY important differences between the two. 40-year old rubbr fuel components will not live well in ethanol fuels, but modern gasoline eats that kind of rubber much more quickly, so regular "gasoline" will also kill the rubber components. Modern rubber compounds (manufactured in the last 20 years) are proof against ethanol, and ethanol will not eat aluminum or viton components, either. If you do not wish to change your tune significantly, try adding about 20-30% E-85 to your pump-premium gasoline. This will significantly increase detonation tolerance, and allow you to run timing like you want to. Switching to E-85 gives you cooler running temps, and the ability to run a tune-up as aggressive as you will remember running with Sunoco 260. Larger jets are required, and if you are running a VERY nasty engine, the "E-85" carbs will probably be necessary. I have had success with just running bigger jets in a standard Holley 3310 carb. This is for street engines, mind you. Much of the new technology being peddled out there is only useful for track use, and will over-fuel a street car. Actual octane ratings vary due to the varying percentages of ethanol in the fuel (85% nominal- as low as 70%), but I have seen 70% fuel at about 105 octane. E-85 is usually about 105-110 octane, and varies from supplier to supplier. In Colorado, the most consistant fuel has been from the Western chain of gas stations. Spark plug recommendations have been all over the place, but one tuner recommends using a cooler plug, as detonation events are possible with the hotter flame front. In street use, I found that I needed a hotter plug, as I wasn't running flat-out all the time.
