What year model A do you have?
I have a Model A 1928 Business Coupe I run the 87 octane gas in with no problems. I've been driving it for over 15 years since I restored it and no problems at all with the ethanol fuel. I used to run the lead substitute in it but that became a hastle and after doing some research it's not really needed. The only problem with Model A carbs is that the Zenith carbs have a tendancy to dump all your gas on the ground when parked. The gravety fed system over powers the needle and seat and if you forget to shut your fuel off when parked, your left with a nice puddle of gas underneath. Nothing to do with the ethonal, just the nature of the beast.
My dad also runs with no problems a 1926 Chevy with not lead sub added and 87 octane from the local gas stations and they all have the ethonal added. The gasoline today all has some kind of lubricant added.