95 Firebird LT1 Running E85

i have been running E85 in the firebird lately, i would put 11.0 GAL. of gasoline and 4.0 GAL. of E85 and the car ran great. I was almost on empty so there was about 2.0 GAL of gas left and i put 5.8 GAL E85 in the car (the most i have ever put in it) knowing that i was going to fill the tank up with Gas later to give me a good mixture. so then i thought i want to see how long i can go with just E85 in the tank. i have drove 85 miles so the Gas is long gone and the car still runs great. Why? Everything i read on the Internet says this is impossible but its not cuz I'm doing it right now. O and i paid $3.42 GAL of E85.

once in closed loop, it will run good - the O2 sensors will get the right mixture, where you need to be careful is WOT, you can lean out and break something
i have 2 camaros (a 96 z28 and a 97 lt4 ss) - got the 97 lt4 on e85 via dyno tuning, and they locked the tune so only they can read it... trying to do my 96 via trial and error.. just need to modify the injector constant and the PE tables i think.. maybe someone who has done this before and add to this...