I have no problem running E-10 in my 454 with a Q Jet, but I only do it when I'm on a trip like to my dad's 70 miiles away. I'll buy the cheap gas to get there and back, but I usually only buy enough to make that trip then just before I get home I'll put 5-10 gallons of real gas in the tank and make sure it's in the carb to sit, not the E-10. In fact, my well plugs leak, so if I let this truck sit for over a day, the float bowls are empty and no gas is sitting in the carb. Now that I think of that, that's probably what has saved my carb. If and when I do build it, I'll use an Ethanol safe carb kit. Sometimes the price difference is .30 cents a gallon for real gas to E-10 and sometimes you're not near a station that sells real gas so you don't have a choice. I'd like to just replace the whole fuel system to be safe up to E-85 even though I probably won't be running that anytime soon. In short, make it Flex Fuel capable if I decided to rejet the carb. In a computer controlled vehicle, it detects that E-85 and tunes accordingly but can't do that on the old ones that are non computer.